Update README...
Fix several runtime problems

Rewrite read_int and read_real to use our own functions for reading
integer and real types. This allows the use of internal buffering
better than trying to fudge about with ungetc and such.

This solves issue with wc.pas and hist.pas.

Add further test for hist.pas.

Update makefile to copy runtime. Move runtests into test/Makefile

Update README
Add more tests

Fix several small bugs:
* Now support '' to make ' in strings.
* Make boolean comparison unsigned.
* Properly detect too many arguments.
* Support otherwise as a case-label.
* Support unary + (adds no extra code).
* Allow "no semicolon" after if when next token is end.