Remove no-longer-used header variable in ass parser
Pass nullptr for the codepage for ass_read_memory

Passing a codepage makes libass convert to UTF-8 even if it's already
UTF-8.
Make missing boost libraries a configure error
Return a rgba string for coloralpha lua controls
Use splice rather than swaps to pop the undo stack
Make BaseGrid::UpdateMaps far less slow
Sort the actor and effect fields. Closes #1715.
Update to moonscript 0.2.5
Flush the clipboard on exit

Apparently flushing immediately after setting the clipboard sometimes
doesn't work.
Eliminate some duplicated exception handling code
Don't return a const std::string from GetData

It has zero benefit and forces an extra copy.
Kill the awkward automatic subtitle format (de)registration
Switch libass URL to github
Move all in-repo deps to aegisub/vendor
Rearrange repository
Add in-repo copy of Lua and use it rather than the system copy

Aegisub needs Lua built as C++ (for stack unwinding on errors). No one
packages it like that, so at the moment we can't actually use systme
packages for Lua.

Fixes a bunch of memory leaks on Automation errors.
Install CSRI and iconv headers rather than mucking about with include paths
Fix compilation with non-bleeding edge boost
Fix crash on startup when the config file can't be written
Add an error check for trying to interact with expired subtitles objects