[utils] add ini-parse adapted from fcitx-utils/desktop-parse
[utils] add conf-desc and conf-file
[utils/ini-parse] helper for get values
[utils/conf-desc] load type
[utils/ini-parse] get int and float
[utils/conf-desc] load desc
[utils/conf-desc] INT_MAX and INT_MIN from limits.h
[utils/conf-desc] load color