Word boundary match

New feature: 
Searching with uppercase letters searches for word boundaries.
This allows for faster searching, e.g. for paths.

Examples:

 * "FoB" will match "foo/bar"
 * "FoB" will match "fooBar"
 * "FoB" will **not** match "foobar"

See the specs for more examples.

Word boundaries are:

 * pascal and camel cased words
 * the characters '/', '\', '_', '-', '.' and whitespace.