Make NonAlphaNumeric more understandable.

Updated EscapeStatTokenizer.NonAlphaNumeric to be more
understandable. Instead of using a '<' character which
serves the purpose of denoting tags I've switched it
for an '!' which makes what the test is testing more clear.
Fix spelling mistakes.
Change tokenizer unit tests to not use \0.

- I've changed the tokenizer unit tests to not rely on \0
when testing. \0 in a lot of cases terminates the tokenizer
functions so checking for them at the end of the test might
result in not catching some errors where it is incorrectly
but still ended up on the \0.
- I've updates those unit tests with text to test that is
more like what it would receive in real situations.
Merge pull request #356 from RickEyre/tokenizer-test-fixes

Tokenizer test fixes
Add start tag state tokenizer unittests.
Remove \t case in start tag tokenizer.

This case is already handled in the first if statement of
the webvtt_start_tag_tokenizer() function.
Add annotation state tokenizer tests.
Add end tag state tokenizer tests.
Add time stamp tokenizer tests.
Add newline to end of files.
Merge pull request #358 from RickEyre/tokenizer-tests-2

More cue text tokenizer unit tests.
Replace 'webvtt_byte' with 'char' for strings.
Remove unnecessary casting in webvttxx/string
Removed unnecessary casts from cue_testfixture
Merge pull request #361 from caitp/byte-to-char

Replace 'webvtt_byte' with 'char'
Replace 'webvtt_byte' with 'char' in README.md
Merge pull request #362 from caitp/readme-fup

Replace 'webvtt_byte' with 'char' in README.md
Remove unused spec dir.
Merge pull request #363 from RickEyre/remove-spec-dir

Remove unused spec dir.
Fix bug in webvtt_class_state() func.

Only add buffer to the classes stirng list if we have parsed
one or more characters into the buffer. Not doing this will
result in situations where we have an empty class string in
the string list.