provide support for visitor pattern
prepare release

all tests pass
added test for complement set
Merge pull request #29 from antlr/prepare-release-4.5

prepare release
Merge pull request #18 from bdkearns/visitor

Support visitor pattern, no impact on existing code I believe
add edit warnings
Merge pull request #30 from antlr/add-warnings-in-generated-tests

add edit warnings
Ensure self.getErrorDisplayForChar always returns str
Merge pull request #31 from antlr/Fix-Unicode-error-in-Lexer.py-#25

Ensure self.getErrorDisplayForChar always returns str
Fix unicode bug

Interestingly, despite the docs, StringIO will NOT accept non unicode
strings
Merge pull request #32 from antlr/Lexer-unicode-issue

Fix unicode bug
add support for $self
moved from $self to $parser

also added generated tests for the above, and moved back to member
tokens
Merge pull request #34 from antlr/add-$parser-support

Add $parser support