Change plot default values w/o modifying source

Now one can change plot default values without modifying the source code: add a plotdefaults.properties file to the resources/properties directory (example file content provided below) with the following structure (default values below -- change as needed)

default_plot_span=120000
default_non_time_axis_max_val=1
default_non_time_axis_min_val=0
dependent_max_val=1
dependent_min_val=1
default_time_axis_padding=0.25
default_non_time_max_padding=0.05
default_non_time_min_padding=0.05

Check-in steps:

Wrote or re-wrote unit tests (Y/N): Y
Ran entire suite of unit tests successfully (Y/N): Y
Verified bug fix with the replication steps in JIRA  or verified the implementation meets the requirement cited in JIRA (Y/N): Y
Code coverage requirements satisfied (new code=80%, changed code=at least as high as existing) (Y/N): Y
Code review date and attendees: 6/20/13 w/ Victor & Rohan
Describe potential impact on other areas of the code: likely none
Describe any test prerequisites for this fix (e.g., restart the database): 
For bugs marked "Regression - Yes", describe the cause of the regression:
Did you modify any pom.xml file? If yes, did you get approval from QA and PM?