extlib version 1.0.0

Major library re-design.

• Changed how dynamic arrays and hashmaps are implemented:
  Now thery are both implemented as macros to make them generic and
  type-safe, and expected a structure definition with certain fields.
  See example folder for more info.
• Added a bunch of features. see README.md and examples folder for
  more info.

You can find the old version of the library by checking out the v0.1.0
tag.