Fixed byte compiling warnings

[sergeyklay]

• Fixed module headers to follow conventions; See https://www.gnu.org/software/emacs/manual/html_node/elisp/Library-Headers.html)

• Fixed byte compiling warnings; Fixes: https://github.com/jschaf/esup/issues/68

• Replaced all the oref with slot-value and properly used quotes; See: https://lists.gnu.org/archive/html/emacs-devel/2016-02/msg01235.html

• Turn byte compile warning into errors on CI stage

• Update documentation

• Bump version

[jschaf]

Nice work! Thanks for maintaining.

[sergeyklay]

You're welcome :)