Restructure test files into a single directory
Add tests on messages
Exclude the current file from inferred paths
Use a special constant to indicate an error
Show proper messages if a proper file is not found
Merge branch 'improve-error-messages' into support-multiple-backreferences

Close gh-8.
Add tests on operator/textobj-user based plugins
Support multiple backreferences (%) in patterns
Add rules for operator/textobj-user Vim plugins

Close gh-7.
Merge branch 'support-multiple-backreferences'
Fix rules for Vim syntax files
Merge branch 'fix-wrong-rules-for-vim-syntax-files'

Close gh-9.
Add release notes on 0.1.0
Update copyright notices
Bump up version to 0.1.0
Merge branch 'prepare-for-0.1.0'