remove dev tags from setup.cfg
add namespace_package 'holland' to plugins/pgsql
add "holland" namespace_package to plugins/lvm/
remove deprecated holland/* subpackages
remove deprecated holland.mysql.option package
update MANIFEST.in for all plugins and holland.core

- ensure *.configspec files are included in each plugin
include templates in plugins/mysql/MANIFEST.in
add holland as namespace package to core package
cleanup contrib/holland.spec
remove skip-unmount option in lvmsnapshot

This is currently poorly implemented and not consistently handled
in mylvmdump, mylvmsnapshot, etc.  Removing for stability reasons
in anticipation of better reimplementation in the near future
Merge branch 'refactor_lvm_plugins' into amsterdam