implemented parser support for regexp operator ~
implemented regexp match operator
Merge pull request #1172 from crate/m/regex-operator

M/regex operator
replace BytesRefInput and BooleanInput with Literals
Merge pull request #1173 from crate/m/no_more_sad_panda

replace BytesRefInput and BooleanInput with Literals
added test for regex functions on non-indexed and fulltext indexed columns
Merge pull request #1180 from crate/h/select-nonindexed-test

added tests for regex functions on non-indexed and fulltext indexed columns
fixed NPE on new boolean literal creation
fixed regex index type variation tests
implemented subscript array notation support
(only 1 array element supported at nested subscript tree)