Allow fractional font sizes.

Closes #1125
File path settings now rank higher than scope settings

A file setting like “src/*.cc” is arguably more specific (and thus more local) than targeting the scope “source.c++”, so it makes sense that the file settings rank higher than scope settings.

Some users also find it natural to target file extensions over scopes, but as TM will store some learned settings with a scope selector, it would previously lead to confusion, when a user was unable to e.g. change tab size for “*.php” (because TM had a learned setting for “source.php”).
Replace iterate macro with new for loop (C++11)

Also use emplace_back a few places.