plug-ins: string fixes
These are small fixes for recent string additions to the plug-ins.
- Add periods and start sentences with capital letter in curve-bend.
- The adjective Lower was getting the same translation as the verb Lower, add a context for languages where these aren't the same.
- Consecutive strings containing
X max
,y min
,ymax
, make them all use same style. - Fix a doubled accelerator and a space accelerator that a) seems non-standard and b) I can't get to work.