Update wings_jp.lang and hiline_jp.lang

wings_jp.lang (+4 squashed commits)
*Update Help message and Tweak commands strings.
*Remove un-used data
*Update and improve translation (Selection groups,Area & Volume etc)
*Did the translation of untranslated part.

Update wpc_hlines_jp.lang 2 string change
*wpc_hline:dialog:26 Change the representation more understandable text.
*wpc_hline:export:2  Change to English String for avoid bug... Because Wings3D's OSX Native dialog not work with Non Latin charactors.
It was added a new option Rotate to the command Snap Image. Thanks to boredom who asked for and oort for testing.
Fix JPG import on Mac

NOTE: JPG import now works on the Mac.
Merge pull request #68 from Micheus/mv/snap_image_rotate

Added new Rotate option to Snap Image command
Merge pull request #60 from tkbd/master

Update wings_jp.lang and hiline_jp.lang
Made the grid size customizable

Many users have asked for an option for customize the grid size. So, now users can define the grid size in the Preferences dialog (General->Grid).

NOTE: Added option to customize the grid size.