Add indication for active switches, pressed keys etc

When listing supported event types that can have a state,
add '*' after the event name if the state is active.
The evdev_trace utility takes also shorter forms of evdev paths

For example "/dev/input/event1" can be shortened to "event1" or
just "1".
The use_low_power_mode setting defaults to false
Do not install gconf schemas if builtin-gconf is in use
Do not save config keys that still have the default value

This way mce package upgrade can change config keys that the
user has not explicitly set to non-default value.
Use helper function for setting high brightness mode

If mce for some reason tries to write out of bounds data to the high
brightness mode sysfs file, it will be logged and capped to valid range.
Do not send unwanted replies to get/set_config D-Bus method calls

If method call message has no-reply flag set, possible method/error
replies are discarded without sending them over D-Bus.
Refactored mcetool

Huge main() and status reporting functions split into smaller chunks.
The mcetool options are now processed in the order they are given.
Dropped session bus support.
Removed dead code.
Merge pull request #41 from spiiroin/display_lpm_config

Low power mode display is disabled by default
Merge pull request #42 from spiiroin/set_config_no_reply

Do not send unwanted replies to get/set_config D-Bus method calls
Merge pull request #43 from spiiroin/tool_fixes

Improvements to mce tools