Port back to Java 8

Improve Readme.

Add nonstandards mode.
Add tests for extensions.
Add relative path extension.

Floats are now correctly treated as dotted keys in the key position.

Newlines are also no longer skipped when parsing key-value pairs.
Added tests for said newly supported number keys.
Multiline strings use their starting row instead of their ending row.

Port back to Java 8

Cleanup API, add QoL stuff, and add date support.

Port back to Java 8