commit resolver progress
temporary commit
add_plugin allows compilation variants

firstly implemented for resolver
cleanup toolsfunc not longer needed in exportsymbols.c

Variants are used by providing additional PLUGINS with underscores
e.g. resolver_gd_gd is a variant of resolver
providing ELEKTRA_PLUGIN_FUNCTION to generate unique names for every
variant

add locking library for all resolver libraries (static with fPIC)
disable test_resolve, it needs internals of the library
make resolver unit test run again

reset to previous behaviour (not taking passwd into account)
fix contract and symbol export
cleanup debug stuff

remove cmake messages
check if placements are correct (with kdb check)
do proper splitting in three variants of resolver
give warning if CONFLICTS debug support was added in resolver
give code how mounting of special resolver would work
Merge branch 'resolver'

add initial support for compilation variants
allow passwd checking for resolver