* Use standard KC_ALGR, remove language-specific redefinitions
* Use ALGR instead of ALTGR in BÉPO and Canadian multilingual keymaps
* Remove BE_LALT, BE_LGUI aliases
* Add standard ALGR defition, remove (re)definitions from language files
* Use ALGR(kc) consistently in ALTGR(kc) aliases
* Non-Nordic keymaps should not use NO_ALGR
* Add standard KC_ALGR definition
* Update docs with ALGR and KC_ALGR
* Update SS_ALGR and ALGR_T aliases
* Clarify the license for files we have signoff on
* Update against the currently signed off files
* Remove unused and not clearly licensed headers
* Replace an #endif I accidentally removed while resolving merge conflicts
By testing I found out that, at least on Linux using the Swedish layout,
two macros present on this file were wrong, for the backslash and pipe
keys. Jack helped me find the correct combination for the backslash and
that led me to the right one for pipe.