Renamed methods with misleading name
Made lexer tokens use raw strings for regex
Allow PyPy to fail due to upstream bugs

See the PyPy repository for details:
Test: https://bitbucket.org/pypy/pypy/commits/75ab5316ff3f42d1821392740f0ff5aa514135a1
Fix: https://bitbucket.org/pypy/pypy/commits/27aa8184f00fe8f13ac71a61a28e1e373e5ef6ce
Merge pull request #12 from Markush2010/cleanup

Small cleanups
Merge pull request #14 from Markush2010/travis

Allow PyPy to fail due to upstream bugs
Implement basic filter syntax `{{ foo|bar }}`
Merge pull request #13 from Markush2010/filter-syntax

Implement basic filter syntax `{{ foo|bar }}`
Add basic auto-escaping
Cleanup docstrings and line breaks
Pretty print AST if debugging is turned on
Merge pull request #15 from Markush2010/debug

Pretty print AST if debugging is turned on
Merge pull request #16 from Markush2010/cleanup

Cleanup docstrings and line breaks
Add Library to register filter functions and allow lookup of those in template
Fix precendence error in lookup_name parsing
Made full name filter and tag lookup work
Merge pull request #17 from Markush2010/filter-lookup

[WIP] Filter lookup