* add doc and testcases for InstrUncache module
* move instruncache testcases under ut_frontend directory
provides classic version and toffee version
* update README, clear commented code
* Add icache compile scripts, waylookup enviroment and revise dir_map.f
* Revise icache top compile script and dir_map.f for normal compiling
* Revise icache ctrlunit script and add ctrlunit test enviroment
* Delete unused script
* Add internal signal yaml and revise its responding code in compile script and iprefetchpipe test environment
* Revise internal signals yaml and its corresponding content in script
* Add mainpipe test environment
* Revise internal signals yaml and its corresponding content in script
* Add missunit test environment
* Add task.get_name
* Revise internal signals yaml and its corresponding content in script
* Revise dir_map for right mapping
* Add icache top test environment
* Add icache docs and its pics
* Add icache pic and interfaces
* Add icache _index.md
* Add icache pics
* Add icache submodule docs
* delete copy pic
whensungoesdown