Change LuaJIT's deployment target back to 10.4

Targetting 10.7 makes the error handler segfault, and targetting 10.4
appears to work fine.
Update ffms2
Write a BOM at the beginning of subtitles to make unpatched VSFilter happy

Closes #1795.
Don't version the executable on Linux

Release branches will continue to use versioned file names, but that
doesn't really make much sense for builds from master.
Use wx events for invoking on the main thread on OS X

Dispatching to the main queue with GCD does not work when there is a
modal dialog active.
Remove the automation thread priority stuff

It hasn't actually been used for anything for a while, and if a single
normal-priority thread can make your system unresponsive it's time to
upgrade to an OS that's isn't garbage.
Ensure the lua state gets closed when running tests

This is required for the gc metamethods to actually get run.
Fix handling for automation debug formatting errors

One spot was missed when converting stuff over to using error_Tag rather
than lua_error for stack unwinding on errors.
add '(Language)' after translated labels as suggested on the forums: http://forum.aegisub.org/viewtopic.php?f=5&t=66925#p91569
update config.guess and config.sub
Change AudioDisplay::style_ranges to a vector

This is faster in all cases except for repainting a very small part of
the display with a very large number of range transitions and simplifies
the code a bit.
Simplify AudioSpectrumCacheBlockFactory a little
Speed up aging the block cache

Keep track of the total size rather than recalculating it every time as
calculating the size actually takes while.
Remove unused things in block_cache.h
Don't use std::min/max in mid()

VC++'s optimizer completely falls down on it for whatever reason.
Fix a bunch of float <-> double conversion warnings
Eliminate a pointless multimap in the cache cleaner
Add simple type -> type name string compile time reflection stuff

This is needed for passing types to the LuaJIT ffi.
Convert the unicode lua module over to using the ffi
Convert the lfs module to using the ffi