Improve helm header prompt
re-factoring helm-gtags--path-libpath-p
Re-factoring helm-gtags-file-content-at-pos
remove space from lighter
Use helm-current-line-contents instead of own code
Re-factoring helm-gtags-set-parsed-file
Re-factoring helm-gtags-parse-file
Re-factoring helm-gtags--find-tag-directory
Re-factoring helm-gtags-find-tag-from-here-init
Re-factoring helm-gtags-complete
Re-factoring helm-gtags-construct-option
Refactoring functions which are related to helm-gtags-select
Re-factoring helm-gtags-token-at-point
use process-file instead of call-process
add .travis.yml for CI
add test file for unit testing
Refactoring for helm-gtags-update
Refactoring helm-gtags-files-candidate-transformer
Do case sensitive matching for highlighting candidates
Use normal symbol instead of keyword symbol

It is difficult to distinguish them from keyword argument.