* Add Files action to template context. (#1198)
* Fixes to testFiles().
- Set os.ModePerm on directories created during test.
- Use filepath.Join() to create directory path.
- Use Fatalf, not Fatal.
* Make additional fixes to test cases.
* Fix test cases to use correct path format.
Dir.Open() in net/http requires '/'-separated paths while
filepath.Join() may produce paths with different separator.
* Remove directory created by test at end of loop.
* Close the FileSystem before returning.
* Initialize names slice to the number of entries.
Also, do not call os.RemoveAll() unless the path to the directory
is a valid one.
* * Added support for environment variables to 'templates' module.
* Fixed flaw in test caused by environment variable ordering during testing on CI.
* Updated some local variables to camel-case.
* Reverted changes to replacer as environment variables are processed elsewhere.
* Removed PrintEnv functionality in favour of documenting using template range.
