#1902 scintilla: matlab lexer doesnt detect invalid block comments fully

[lostbard]

In matlab block comments should start with %{ with potential spaces before and after on the line.
Likewise block comments should end with %} with potentail spaces before and after.

Ie: anything with non spaces in it would be a line comment, not a block comment.

Current lexer already checks that a block comment starts with [spaces]* %{, however does not check to the end of the line.

Patch attached that checks to end of line

[Neil Hodgson]

Committed as [156423] with some minor changes to white space in lexer source.