Regex support match_all
Adding match_all to exports.jl
Modifying match_all to plug into the iterators.
Adding tests for regex match_all.
Modifying match_all to matchall to follow convention.
Renaming to matchall in test as well.
Adding support for overlap option.
Removing useless is_utf field
Merge branch 'master' into nutsiepully-match_all_regex

Conflicts:
	base/regex.jl