Added design parameters for each ui_element and global design parameters - naming conventions     + params specific an element - prefix it with the class name in lower case     + use 'org' and 'size' keywords as var names to make behavior explicit.
Added design parameters for each ui_element and global design parameters
- naming conventions
    + params specific an element - prefix it with the class name in lower case
    + use 'org' and 'size' keywords as var names to make behavior explicit.

Fixed
  - on_color for Thumbs (previously was magenta - due to misplaced decimal point)

TODO
  - step slider is broken - check changes to Sync Val or changes made due to design param variables for next commit.

papr/pyglui,pupil-labs/pyglui,paulmthompson/pyglui,papr/pyglui,pupil-labs/pyglui