remove:c50:remove all the unneeded files

Merge pull request #759 from LiteOS/develop

merge develop branch to the master branch

Merge pull request #727 from zhanzhan2000/at

At

Merge pull request #685 from w00164089/develop

Add the statck size of liteos timer task

Merge pull request #629 from jimscen-wang/develop

modify lts shakehand timout for tcp.

At (#556)


* 修改差分还原包

Merge pull request #512 from jimscen-wang/primary

fix pclint

Merge pull request #430 from zzkd1991zzkd1991/develop

Develop

Merge pull request #400 from l00438842/develop

1、增加bind_quit 2、psk_idid_len使用strlen计算 3、申请的内存进行初始化

Merge pull request #365 from developer2324/develop

update Developer Guide