Fixes to configuration handling

[immortius]

Addressing #1843

• Extracted out RootConfig from Config, separating handling of config load/save from the bean class used to hold the root of the configuration.
• Moved default configuration values into a resource.
• Changed serverPort configuration to be overridden by a system property during load.
• Changed saveGameEnabled configuration to be overridden (but not saved) by a system property.
• Removed TransientConfig as no longer needed
• Mapped the existing Terasology commandline options to set system properties.

[GooeyHub]

Refer to this link for build results (access rights to CI server needed):
http://jenkins.terasology.org/job/TerasologyPRs/193/

Build Log
last 5 lines

[...truncated 2164 lines...]
Build step 'Publish JUnit test result report' changed build result to UNSTABLE
[ANALYSIS-COLLECTOR] Computing warning deltas based on reference build #192
Notifying upstream projects of job completion
Setting status of 03bd6d7bd309bf6c60556bf369305c3738c6d509 to FAILURE with url http://jenkins.terasology.org/job/TerasologyPRs/193/ and message: Merged build finished.

Uh oh, something went wrong with the build. Need to check on that

[GooeyHub]

Refer to this link for build results (access rights to CI server needed):
http://jenkins.terasology.org/job/TerasologyPRs/194/
Hooray Jenkins reported success with all tests good!

[msteiger]

Looks good to me.