Related to (closed) Issue #2094 on template inheritance. This PR adds a new function called "import" which works like "include", except it only takes one argument and passes it to the referenced file to be used as "." in that file.
* Update tplcontext.go
Add {{ render "/path/to/file.ext" $data }} via funcRender
* Update tplcontext.go
* Refactor funcInclude, add funcImport to enable {{block}} and {{template}}
* Fix funcImport return of nil showing up in html
* Update godocs for and