Support for language-mapping `lmap`

[xged]

from :h language-mapping:

":lmap" defines a mapping that applies to:

• Insert mode
• Command-line mode
• when entering a search pattern
• the argument of the commands that accept a text character, such as "r" and "f"

Vim-sneak accepts text characters therefore should support lmap.

[justinmk]

Is this different than 'keymap' (already supported #47)?

[xged]

'keymap' internally uses lnoremap, so it should not be different, but it does not work for me (my &imcmdline is 1 (on), but command-line (:) lmap allways restarts to off).

[justinmk]

I'm going to mark this as patcheswelcome for now, because I'm not even sure if anyone uses the keymap feature. Thanks for the report.

[vinszent]

Not sure if this is the same issue, but I had problems with vim-sneak when using set langmap=hk,jh,kj to fit the colemak layout better. Setting set langnoremap fixed my issues.

[justinmk]

@Ippytraxx I believe the only reason set langnoremap even exists is for "backwards compatibility". There's virtually no reason not to use set langnoremap. See also tpope/vim-sensible#93

Thanks for the report too.