Revert "Check if hook templates exist or are valid"

This reverts commit 7e9e709260c321456367bc165abed1dcf6a26dbd.
Revert "You can now overwrite the upload template"

This reverts commit 76a129e9a31b24d34c9e0ee6fa594ae222bc3cd6.
Revert "Fixed a bug with rendering hook templates"

This reverts commit e8b7d29d78f43714bc912efcc34053ab3f4d2b61.
Revert "Added a "registerImportTemplate" hook, so you can have your own mapping template for the import plugin"

This reverts commit d90dcc5596d4c86a829decb2055b9446dac7efa2.