Snapshot floater changes

* Added a radio button for "Post to my.secondlife.com feed"
* Moved the snapshot to the top of the floater.
* Increased the size of the snapshot to match the size used in V3
  (floater is only 4 pixels wider though).
* Disable the "Temporary upload" checkbox when the Destination isn't the
  inventory.
* Update the shown Upload Fee to L$ 0 if temporary is checked.
* Added a size chooser for the Feed destination, using exclusively
  preset sizes with an aspect ratio of 4:3.
* Added two new preset sizes: 1024x1024 for texture uploads, and
  1680x1050 for save to disk.
Large snapshot update (part 1)

This commit concentrates on remembering what parameters
where used for the last snapshot (the actual source, not
the formatted one), thus - the parameters passed to
rawSnapshot() - and then shows this snapshot as if it
was just made whenever the UI parameter selection matches.
The result is that the user can make a snapshot, save
it (for example) to their harddisk and then change the
destination and upload the same thing as snapshot.
The code tries hard to make this possible by automatically
adjusting the UI parameters to match every time the destination
is changed PROVIDED it was already saved or uploaded before.
If a snapshot wasn't saved and one changes destination
then this currently doesn't happen (by you could manually
make the parameters match, and still upload it). Also, if
the resolution is changed for a particular destination then
it won't automatically adjust it again.

Obviously, snapshots are no longer refreshed when changing
destination etc. You have to explicitly click "Refresh
Snapshot" before the last one is deleted / replaced.

The Debug Setting variables reflect the (last) manual choices
in most cases (set in the onCommit functions). If such a choice
is not allowed for a different destination then the UI is
changed to reflect the current behavior and the checkbox is
disabled so the user can't change it anymore. Then, if they
change destination back - the Debug Setting variable is used
to remember their last preference. A new Debug Setting has
been added for this purpose: SnapshotLayerType (colors or depth).

The old mSnapshotUpToDate has been removed and replaced with
mShowFreezeFrameSnapshot. The old getSnapshotUpToDate() now
returns something else (than mShowFreezeFrameSnapshot), namely
whether or not the current raw snapshot was taken with the same
parameters as are currently set in the UI.

The unused functions getImageAspect() and getAspect() were
removed.

mCurImageIndex has been deleted. Index 0 now means "the last
snapshot" and index 1 is temporarily used for the Falling Away
animation.

mDataSize was renamed to mFormattedDataSize.

The size spinner arrows are now disabled too whenever the spinner
edit field is disabled.

A bug in Freeze Time was fixed, where avatars would still
rotate around their axis in place (and without that their
attachments moved!)

Pressing ESC would return keyboard control to "walking"
for the own avatar with the above as result for the own
avatar. We now intercept ESC and use it (in Freeze Time mode)
to return to the cammable preview when a 2D preview was
being shown.
Fix cancelling "Save" while "Keep open after save" is unchecked.

This causes a failure to save local file, or when clicking
Cancel in the file chooser, to keep the image and keep the
snapshot floater open so a retry to save the image can be
attempted.
Allow setting a custom size when uploading a texture.
Merge branch 'master' into llwebprofile
Snapshot fixes and improvements.

* Allow to pass -1 to LLImageBase::reallocateData too (default parameter),
  causing it to allocate what is necessary for the size set (same
  behavior as allocateData).
* Speed up LLImageRaw::scale with factor 2 or 3 by copying the data less
  often and calling LLImageBase::reallocateData instead of destroying
  and recreating always.
* Fix gl_rect_2d to not decrement top and right with one pixel.
* Remove the vague "Constrain Proportions" checkbox and replace it with
  a new combo box and spinner to explicitly set the target aspect ratio,
  allowing to set it also to something different than either the window
  aspect ratio (ie, 1.6) or the target image dimension (1.0 for textures)
  which was totally lacking when, for example, uploading a profile image
  (which needs to be 4:3). This also allows to show snapshots on prims
  of arbitrary aspects.
Large snapshot update (part 2)
Merge branch 'master' into llwebprofile
In Freeze Time re-show fullscreen preview when clicking thumbnail.
In FreezeTime mode, keep avatars that TP away.

If an avatar TP's away (or quits), he will not
disappear anymore from a frozen scene. Unfreezing
makes him disappear of course (and clean up).

Known bug: if during Freeze Time mode someone
TPs away and then back, then he becomes a cloud
after Freeze Time is ended, which can only be
reset by another teleport (or relog) from either
the cloud or the one seeing him as cloud.
I decided not to fix this, cause there are things
with a higher priority and this - if it happens
at all - is rare and easy to recognize and work
around.
Large snapshot update (part 3)
Add filtering for curl debug output.

Add CURLTR debug channel for libcurl API calls,
and use CURLIO only for libcurl debug output.
Note: need to set gDebugCurlTerse to true for
filtering to take effect, then pass 'debug_on'
to the LLHttpClient methods that require debugging.
Fix cookie handling.

Cookies are now collected during redirects, one the last cookie
of a given name is kept. Cookies are then set by looking for
the right cookie name (instead of what viewer 3 does: just
use the last cookie that was set).

This fixes the merchant outbox.
Fix outbox notifications.
WIP: floater_snapshot_feed.xml and code.

This is just a skeleton, roughly copied from the Postcoard
code, which is very similar. Nothing in indra/newview/llfloaterfeed.cpp
has been changed yet, apart from a few deletions (to make it compile)
and the literal replacement of "Postcard" with "Feed".
indra/newview/llfloatersnapshot.cpp was updated however to
open the new floater when one tries to upload a snapshot to the feed.
It is still needed to make a callback to saveFeed(), or rather to
move that function to the saveFeed that is in llfloatersnapshot.cpp.
Compile bug fix
Disable upload/send button immediately.

Immediately disables button and reenables it
again when upload/save was a failure.
The callback is now ignored if the snapshot
was refresh in the meantime.
Improvements!

Fix CMakeLists being out of order.
Add setting SnapshotFeedAddLocation to keep track of user's preference whether or not to include location in uploads to profile feed.
Clean up LLFloaterFeed to take only what it needs, also gave it a boost~
Remove saveFeed() from LLFloaterSnapshot, removing the dependency on LLWebProfile.
Compile fixes for LLFloaterSnapshot.
Prettied up the upload to feed floater.

TODO: Does Location even work? I can't get it to appear, never seems to get used right in v-d either.
Always remember to save after making a change. (Location works now)
Do not attach cam to avatar in Freeze Time mode.

We do, and the avatar moves then the cam jumps
away from the frozen avatar to where it really is.

Unfortunately, it's still not possible to attach
the cam to moving objects with this patch.
Also, scripted changes to objects are still visible,
like changes in local lights of texture full brightness.