Merge pull request #12 from FreekDB/master

Fixed Checkstyle issues and other small changes
Changed application flow to accommodate following (error) condition: 
No initial reports found in report directory satisfying given date
range.
Added support for changing progress log file path - after selection of
new report directory. 
Working on ViewerFrame.java for GUI layout and removing duplicate code
(the source file is huge at the moment).
Added support for removing progress log file listener - in case new root
directory is selected.
Added chartMouseClicked(ChartMouseEvent arg0) in ViewerFrame.java -
Assigned Index to the Chart in ChartUnit.java to address the following: 
Clicking on right part of the main table (on a graph) does not select
that row. (And therefore does not show that graph large at the bottom).
Work in progress for assigning appropriate Layout for the Report Viewer
GUI components.
Added TODO comments for layout (to be removed after finishing the
layouts). 
Prefer to use BoxLayout (horizontal/vertical) - since it is simple and
effective.
Adding constants for WIDTH and HEIGHT dimensions
Using setPreferredSize for UI components
Explicitly assigned BoxLayout to controlPanel and controlFrame (instead
of using Box as the container) 
Added rigid areas in the Box Layout
Added BoxLayout for: 
zoomPanelButtons (In[+], Original, Out[-])
zoomPanelForm (Min, Max, Zoom X Axis)
zoomPanel
ProgressLogReader: added some Javadocs, renamed singleton instance to INSTANCE and removed a tab character.
MetricsParser: changed import order.