add the doc the page about environment variables
add the doc the page about key maps
add the doc the page about developer tools and some functions
move the window statement to displaying_images
add the doc the page about creator defined statements
add doc about after_warp and some functions
add doc some pages
add doc some statements equivalents
fix
fix message
enable translation of lancher
allow_translate_lancher
add doc about showing a window during a transition
Port after_checkout.sh to non-Linux Unixes

`after_checkout.sh` has been using `readlink(1)` to get an absolute path (with
no symlinks) to the renpy root directory.  Unfortunately, `readlink -f` is a
GNU extension, and thus unavailable on the BSDs, including OS X.

There are[0] a number of options for those systems.  While an exec out to
Python seems like overkill (and is, in fact, a bit slow on my system), the
delay is small enough to not be a problem in a one-time script like this.
Additionally, it seemed silly to include a dozen-line shell function just for
this one usage.  Plus, we know for certain the user has Python, because
otherwise they couldn't run Ren'Py. ;)

I included the parens around `print` just to make sure it works with both
Python 2.x and 3.x.  I doubt this matters, but I figured I might as well.

If we stop caring about resolving symlinks, this entire line can be replaced
with `$PWD##*`. [1]

[0]: http://stackoverflow.com/q/1055671/120999
[1]: http://stackoverflow.com/a/1371283/120999
Merge pull request #196 from xiongchiamiov/port-after-checkout

Port after_checkout.sh to non-Linux Unixes
Merge pull request #198 from vbkaisetsu/fix-doc

fix doc that doesn't contain needed line break
Merge pull request #191 from kyouryuukunn/allow_translate_voice_sustain

Allow the translation of "Voice Sustain".
Properly deliver the error message when no build packages are selected.

Fixes #197.
Merge pull request #193 from kyouryuukunn/fix_message

Fix missing wxPython message.
Merge pull request #189 from kyouryuukunn/add_doc3

Add doc3