Add specta and expecta tests
Add gitignore.
WIP: First attempt at string support. Specta tests need some improvement.
Fix capitalize.
Fix trim.
(Split) Changed split behavior to split at whitespaces. Add splitAt to specify a separator string. Tweak tests.
Removed UnderscoreSpec.m. Inlined strings into test cases for better readability.
Add split. Refactored signature of uppercase, lowercase, capitalize and trim. Add tests for all functions.
Shortened class method names (ditched the 'string' prefix).
Merge pull request #46 from robb/string-support

[WIP] String support