This narrows the range of Unicode codepoints fish reserves for its own
use from U+E000 thru U+F8FE (6399 codepoints) to U+F600 thru U+F73F (320
codepoints). This is still not ideal since fish shouldn't be using any
Unicode private-use codepoints but it's a step in the right direction.
This partially addresses issue #2684.
When an error occurs midway through a token, like abc(def,
make the caret point at the location of the error (i.e. the paren)
instead of at the beginning of the token.
This change moves source files into a src/ directory,
and puts object files into an obj/ directory. The Makefile
and xcode project are updated accordingly.
Fixes#1866
