Ignore "smart selection rule" if it's range

Thanks to filterfalse.
Document FileView::user_selection field
Merge branch 'make-ga-range-friendly'

Ignore "smart selection rule" if it's range.  Also document related
flag.

Thanks to filterfalse.
Pass error code of vifmrc-converter through vifm

Thanks to Hendrik Jaeger (a.k.a. henk).
Fix handling of missing files in vifmrc-converter

Thanks to Hendrik Jaeger (a.k.a. henk).
Merge branch 'fix-error-report-from-vifmrc-converter'

Fix error handling regarding vifmrc-converter.

Thanks to Hendrik Jaeger (a.k.a. henk).