compat: fix for multiple freeing in __ni_suse_free_globals()
[logging] corrected --log-target destination parsing

- Fixed to correctly compare complete strings
- Changed to a more common syslog[:facility:options]
  instead of the previous syslog[:options:facility].
- Reworked to use more readable/generic table mapping
[wickedd.8] documented --log-target details
util: New function ni_file_exists_fmt()

It can be used to create a concatenated pathname and
check for existance of a file.
client: Changing ifconfig reading and loading

New file: read-config.c

New function ni_ifconfig_read() added as well as
multiple other read() function for different type of
config source.
config: Change config sources handling logic
client: Add show-config parameter

show-config displays configs (pre-parsed to xml)
from all types of sources.
[config] Streamline extension runtime dir creation

1. Use /var/run/wicked/extension/EXTENSION_NAME
2. Do the creation from ni_extension_statedir(), rather than adding
extension specific functions to config.
[system_update] Hostname update from lease

Update system hostname from first arriving lease with hostname field set,
and emit hostname updated signal. Subsequent leases not allowed to set
hostname unless:
  i. lease that set hostname has been removed
  ii. arriving lease is an update
[netinfo] Create extension statedir only once
rpmlintrc: Removed obsolete content (bnc#783932#c18)
version 0.5.1