Only show hours if necessary

Don't show e.g. 00:00:02 in timestrings as it looks clumsy.
Add rtl to labels in MainWindow.js

Check the direction the widgets are using.
Add support to all the labels.
Fix Bug 724455 The window size is too wide

Remove manual setting of child widget widths from the MainWindow.
Remove manual setting of widths from the the waveform.
Fix Bug 724455

Remove manual sizing of widgets from Waveform.js
Clean up whitespace
Fix Bug 724455 The window size is too wide

Remove additional resizing code
Style and whitespace fixes