TOML: Fix highlighting of string escape sequences
Review Request #130048 - Created March 25, 2017 and submitted
The rules were using
HlCStringChar, which matches on backslash followed by one of
abefnrtv"'\but TOML only supports
bfnrt"\so it would wrongly highlight eg.
\aas an escape sequence.
HlCStringCharwith an explicit regex matching only the supported escape sequences, including
\Uxxxxxxxxfor Unicode hex chars. I also added a rule to mark any other backslash sequence as an error.
Looked at the HTML result in kate-syntax-highlighter, and editing in Kate (an old version not using this framework).