Rasm Z80 assembler

[roudoudou]

new release

https://github.com/EdouardBERGE/rasm/releases/tag/v2.3.6

v2.3.6
new directive SUM16 to create 16-bits checksum (useful for manual Amsdos Header)
 new directive FREEQUOTES (when you are bothered with command line option)
v2.3.5
new behaviour for USED tag of aliases, variables and labels with IFUSED, IFNUSED
new optimisations in aliases processing (benefits for all kind of calculations)
new autotests (TDD, end-to-end, UT and exploratory tests)