"i3-colors Project Todo List"

Refactoring [1/2]:
- Change src/parser.py name => now config.py
- Improve function/variables names
YAML Theme Parser [1/2]:
- Improve yaml theme loader reliability
- Allow several metadata
Theme applying algorithm [1/3]:
- Improve efficiency
- Bugs may appear here! Found them…
- Assume that theme to apply is well formated (checked in YAML Theme Parser)
- If there is no "colors" field in "bar" section, we still need to apply theme
General [1/2]:
- Improve user API
- Allow -r option (restart i3)