Misc new functionality

[wadetb]

New PR with changes by @karimbahgat, CI enabled and merged to master.

Added:

• more clearly dividing/grouping the various funcs and methods with comments
• array comparison funcs
• array retrieval funcs
• array iteration
• getitem support for boolean and numeric indexing
• boolean comparisons for arrays and single numbers
• math operators for arrays and single numbers

Rewrote:

• array math funcs