Refactoring: Move dev & prod runmodes to const

Retrieve session identifier from cookie and query parameters

Add link to russian

Add link to russian

clean code in docs.go, error.go, filter.go and hooks.go

simplfy config.go and controller.go

cors test benchmark doesn't use b.N

compress level test fixed

为orm接口添加注释

Fix joins for reverse(many) with custom pk

Revert "go test fixed"

go test fixed

clean compliated codes, refactor if sections in app.go

Added MaxMemory limit to CopyBody() Supersedes #1484

Beego only uses the MaxMemory flag when using go's built in functions
for parsing forms. However the CopyBody() function have no limit an will
coppy anny amount of data into memory using ioutil.ReedAll() on the
request body whitout anny size validation or limit.

This fix wrapps input.Requst.Body in a LimitedReader using the same
memory limit as ParseFormOrMulitForm()

 - Also add test covering the issue