Implemeted detection of bracket scopes

This is implemented and documented in `bracket_scopes` module.
A simple plugin that uses it is also implemented. However, for some
weird reason it hangs up Sublime when (Sublime) scope detection is
enabled. Currently looking into it...
Fixed 'unexplainable' Sublime hangup

Turned out to be a stupid infinite loop. No magic, go along.
Removed redundancy in the bracket search loop

Distinct `offset` and `point` are no longer needed.