relax SVN archive

Converted the peak list button from text to bitmaps.

Imported the 48x48 icons.

Shifted the peak list button sizes into one local variable, 'size_button'.

Added the 48x48 icons to the icon paths.

Added a few icons for addition and removal of data.

Fix for sync_ds().

The relaxation times were not converted to proper strings.

Initialised the list_file and relax_times data storage variables to be populated with ''.

The length is set to the hardcoded value in self.peak_list_count.

Variable abstraction.

The following GUI elements were renamed:
r1_list -> field_rx_list
r1_time -> field_rx_time

Shifted the hardcoded peak list element count from the relax data storing into the class namespace.

The file_list and relax_times structures should be dynamically updated with the 'Add' and 'Refresh'
buttons.

Built the sync_ds() method for synchronising the Rx frames and the relax data store.