Add "LOD Override" option

Adds an "LOD Override" option to the entity and model parts to set their
LOD manually. When set to -1 (the default), the engine handles which LOD
should be used (ie normal behaviour).
Add beam part option "Use Endpoint Offsets"

When checked, the beam will use the endpoint part's position offset and
angle offset to determine where the endpoint of the beam should be,
instead of ignoring them. Default is off (to retain current behaviour on
existing costumes)
Add custom animation part

This part uses boneanimlib to play animations created by the animation
editor on players. (Animation editor changes not included in this
branch)
Add animation part option "Reset on hide"

When unchecked, the animation part will not set its parent entity to
sequence 0 on hide, allowing users to switch between two sequences
fluidly using two animation parts with events. Default is checked to
retain prior behaviour on existing costumes.
Fix looping on webaudio part

Wasn't looping before, now it is.
Add pace tool "square model scales"

Adds a pace tool that will square the scales of all parts who have a
Model field selectively if that field contains a given string. This tool
will help repair costumes that were created between Apr 04 2014 and July
08 2014 that did not use legacy scale. A filter is being used to select
which models to scale because not all models will need to be scaled back
(in many cases, only default.mdl will be- which is why it is the default
string).
Add pace tools that import pace tools

Yo dawg...

Adds pace tools that allow superadmins to import pace tools from a local
file or an external URL. It only imports them into the editor of the
client who ran them.

(The superadmin restriction is present to deter people from stealing
other's pac costumes. It's obviously still possible, but I don't want
this to make it any easier to do. In singleplayer the local player is a
superadmin so they can still use it there.)

See the following gist for some example importable pace tools:

https://gist.github.com/suchipi/632a3bfb8a29269c1ddb
Update animation editor

This commit makes several changes:

-Remove console command "pac_in_editor" and use the net library to
transmit this information instead (this is used for the overhead "In
Editor" text).

-Replicate this behavior within the Animation Editor.

-Add a "Parsed Skeleton" option to the animation editor that allows
users to use any bone structure their current player entity has.

-Disallow creating an animation without a name, which would cause errors
later on.

-Don't display boneanimlib animations that were created by the
custom_animation pac part

-When editing a sequence, t-pose the player so the user has a proper
frame of reference

-Automatically save backups of the current animation when the editor is
closed

-Allow any user to use the animation editor

-Preserve frame length when cloning a keyframe

-Various bugfixes
Disable legacy text

Outdated (and people have been complaining about it)
Merge pull request #67 from suchipi/patch-disable_legacy_text

Disable legacy text
Merge pull request #59 from suchipi/patch-pace_tool_square_model_scales

Add pace tool "square model scales"
Merge pull request #60 from suchipi/patch-webaudio_part_fix_looping

Fix looping on webaudio part
Merge pull request #64 from suchipi/patch-custom_animation_part

Add custom animation part
Merge pull request #62 from suchipi/patch-animation_editor

Update animation editor
Merge pull request #63 from suchipi/patch-beam_part_use_endpoint_offsets

Add beam part option "Use Endpoint Offsets"
Merge pull request #65 from suchipi/patch-animation_part_reset_on_hide

Add animation part option "Reset on hide"
Move Lod Override into the "appearance" category

I forgot to do this earlier (since I was retracing all my steps to make
these new PRs)
Change condition for allowing pace tool importing

Instead of checking if the player is a super admin, check if
sv_allowcslua is 1. If not, show an appropriate error message.
Merge pull request #61 from suchipi/patch-pace_tool_import

Add pace tools that import pace tools
Merge pull request #66 from suchipi/patch-model_and_entity_parts_LOD_override

Add "LOD Override" option