When launching Aegisub from Finder (but not via open), using the UTF-8
version of the locale breaks things for whatever reason, but fortunately
it's unneccesary as paths on OS X are always UTF-8 even if the locale
isn't.

Closes #1685.

Color matching to dummy video makes zero sense, and setting it to None
results in breakage when someone opens dummy video for an already
typeset script.

Closes #1690.

Newlines in the text are converted to \N, so no reason not to allow it
there.

Closes #1691.

FindExInfoBasic was added in Windows 7, not Vista.

--enable-stl replaces the implicit conversion to char/wchar_t* with one
to std::[w]string. This breaks conversions to boost::filesytem::path and
makes some ternaries ambiguous (which GCC helpfully reports as no
conversion existing rather than an ambiguous conversion).

Modifying the contents of a text control after IM processing happens in
the same cycle of the event loop seems to be seriously broken. Work
around this by disabling IM processing for time edits, as it should
never be relevant for them anyway.

Closes #1679. Closes #1680.

Move downloading the ICU data file to the ICU project, since that's the
only thing that was left.

Grabbing them from the package's src directory just adds another step
that needs to be done manually whenever a translation changes.

VS Express Edition doesn't support F#.

Don't delete the old copy of the file until after the new version is
committed to avoid a use-after-free when code tries to do things with
the active line in a COMMIT_NEW handler, as just trying to avoid doing
that hasn't really worked out.

The default Lua include path is encoded with the local charset rather
than UTF-8. This causes problems when the working directory includes
non-latin-1 characters which are valid in the local charset, as Aegisub
expects the string to be UTF-8. As the default path isn't very useful on
Windows (on other platforms it could potentially include things like
luarocks-installed modules), just clear it.

Closes #1676.

Cuts the total runtime of the configure script from 19 seconds to 5
seconds for me.

Boost.thread sometimes fails to link without this.