fix wrong if expression in link_tag
Merge pull request #3050 from emmanuelgrognet/develop

fix wrong if expression in link_tag
Fixed wrong url for Style Guide in Contributing Guide
Adjust docblock of load_class()

refs c26b9ebb00e29be2e972fece3bcf73d33249a64b
Merge pull request #3055 from ilatif/develop

Fixed wrong url for Style Guide in Contributing Guide
Merge pull request #3056 from vlakoff/docblock

Adjust docblock of load_class()
[ci skip] Add a note to CI_Model::__get() (issue #3046)
Simplify code in get_config()

Exact same behavior. The reference was just redundant.
Merge pull request #3053 from vlakoff/get_config

Simplify code in get_config()
Fix caching of MIME config

* in get_mimes(): was missing isset() test
* in Email->_mimes_types(): static cache of reference was noneffective

refs 6ef498b49946ba74d610b3805fb908b163a7f03a
Remove static cache in Email->_mimes_types()

Saving one function call isn't worth the code overhead.