initialization of Pmodules environment reviewed

- introduce new configuration file ${PMODULES_ROOT}/config/Pmodules.conf
- move as much as possible from profile.bash and init/bash to
  modulecmd
- expose less environment variables to the user

Pmodules/profile.bash.in

@@ -3,36 +3,11 @@
 # The following settings are system defaults. They can be (re-)defined
 # in a system wide profile or in a user's profile.
 
-# set groups which should be available after initialization
-: ${DefaultGroups:='Tools Programming'}
-
-# set releases which should be available after initialization
-: ${DefaultUsedReleaseStages:='stable'}
-
 # set default version
 : ${PMODULES_VERSION:=@PMODULES_VERSION@}
 
-#############################################################################
-#          N O   C H A N G E S   B E L O W   T H I S   L I N E !            #
-#
-# Notes:
-#	- PMODULES_ROOT is derived from the location of this file.
-#	- Some for PMODULES_CONFIG_DIR.
-#	- The Pmodules software must be installed in
-#	  ${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}
-#
-
-export	DefaultGroups
-export	DefaultUsedReleaseStages
-export	PMODULES_VERSION
-
-declare -x PMODULES_MODULEFILES_DIR='modulefiles'
-declare -x ReleaseStages=':unstable:stable:deprecated:'
-
 declare -x PMODULES_ROOT=$(cd $(dirname "${BASH_SOURCE}")/.. && pwd)
-declare -x PMODULES_CONFIG_DIR=$(basename $(cd $(dirname "${BASH_SOURCE}") && pwd))
 declare -x PMODULES_HOME="${PMODULES_ROOT}/Tools/Pmodules/${PMODULES_VERSION}"
-declare -x PMODULES_DIR="${PMODULES_HOME}"
 
 test -r "${PMODULES_HOME}/init/bash" && source "$_"