Tweak Resources menu to be not shown when all resources are hidden

Signed-off-by: crynobone <crynobone@gmail.com>
Fixed unable to use Publisher FTP since Illuminate\Filesystem\Filesystem::makeDirectory() throws PHP error when creating directory failed. Closes #60.
Simplify the request via Extension::isWritableWithAsset() helper and fixed test cases.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.0'