[clike mode] Fix C++11 multiline string parsing bug

The issue can be seen on http://codemirror.net/mode/clike/index.html. In the C++ raw_string line, place the cursor after 'delim(' and type '('. Currently this causes a regexp error, which this patch fixes.
[clike mode] Simplify regexp character escaping

Issue #2594
Don't handle character bindings when ctrl is down

Issue #2587
Enable hiding the cursor
Also bail out of keypress events when on mac and metaKey is down

Issue #2587