Modified "split at cursor" so it trims off whitespace around the split point. Fixes #523.

Originally committed to SVN as r1689.

aegisub/changelog.txt

@@ -123,6 +123,7 @@ Please visit http://aegisub.net to download latest version
   o Tweaked the behavior of the margin boxes, now they no longer show padding zeros. (AMZ)
   o Actor and Effect fields now show a "ghosted" caption saying their name when they are not focused on and blank. (AMZ)
   o Added a "Commit" button that duplicates the Enter/Ctrl+Enter functionality, since those shortcuts were not obvious to everyone. (AMZ)
+  o The "Split at cursor" functions now trims off leading/trailing whitespace around the split point. (TheFluff)
 - Changes to Fonts Collector:
   o Changed the font searching engine to something slower, but far more reliable. (jfs/AMZ)
   o Added option to just verify if you have the fonts. (AMZ)

aegisub/subs_grid.cpp

@@ -1260,8 +1260,8 @@ void SubtitlesGrid::SplitLine(int n,int pos,int mode) {
 
 	// Modify text
 	wxString orig = n1->Text;
-	n1->Text = orig.Left(pos);
-	n2->Text = orig.Mid(pos);
+	n1->Text = orig.Left(pos).Trim(true); // Trim off trailing whitespace
+	n2->Text = orig.Mid(pos).Trim(false); // Trim off leading whitespace
 
 	// Modify time
 	if (mode == 1) {