Ability to add non-lanuage-specific project markers.

[gegoxaren]

Is your feature request related to a problem? Please describe.

Having versioned code, or code versioned with non-supperted VCS systems makes the plugin fail. Thus, it would be good to have the ability to add markers that apply to all languages.

Describe the solution you'd like

Match havnig support for wildcard matching in the in g:LanguageClient_rootMarkers, (i.e. mathc on '*':

Describe alternatives you've considered

Adding g:LanguageClient_genericRootMarkers that only takes a list of markers.

Additional context

I am managing a project that does not use git, hg, or svn. (namely Breezy, for a Bazaar project)

I am using the Meson build system. (so searchign for the top level meson.build could also work,)