private: improve the expression of macro CEIL_DIV

Patched by: Kuang-che Wu <kcwu@csie.org>
Reported by: Bo-cheng Jan <school510587@gmail.com>
Add new API chewing_cand_String_by_index
Add clean_userphrase in testhelper
Fix wrong test case error message
Add test cases for PhoneFromUint
Update .editorconfig
Add create_keystroke_from_text.py

Closed #72
Add performance.c to test performance
Fix Typo