Add: Add option -p for ppa installation indicator.
Mod: Use context instead of environment.
Add: Add variables and functions to install fonts.
Add: Add variables and functions for Python.
Add: Add comment for python variables.
Add: Add useful Python libraries for memo.
Mod: Formatting.
Mod: Code cleanup.
Add: Add variables for modules.
Mod: Add comment in the end to solve the '_' problem.
Mod: Use -b for basics.
Add: Add function usage().
Add: Add parse opts and do operations part.
Fix: Fix two bugs as listed.

* Remove non-UNIX character
* Call array function as func array[@]