Don't allow entering incomplete parser configuration.

Prevent entry of parser settings that don't contain e.g.  the files
argument.  This is not complete validation of the definition's
correctness, but it's already better than nothing.
Update LetsMove dependency.
OS X: Add REKit dependency.

This is very useful for "hot-patching" wxWidgets' internal Objective-C
classes to tweak them to do something slightly different, without having
to modify the wx library itself.

Use the work-in-progress REKit branch, which doesn't conflict with wx's
handling of the first responder.
OS X: Complete languages case-insensitively.

NSComboBoxCell uses case-sensitive search for completion and there's no
way to customize this.  Use REKit to inject case-insensitive
completedString: implementation.
Update wxWidgets.

Fixes annoying OS X log messages about fonts and a few other issues here
and there, as usual.
Set eol-style of *.sh to LF.

Bash will fail with scripts in CRLF format; therefore always use LF for
such scripts.