FIX css / layout issues

line height in pre
alignment of textarea with pre at top
border color of textarea
only vertical resizing of textarea
replaced wrong id=" " with class in many places
Even better CSS

red/green indication of right/wrong much more visible
more inconsistencies solved
Rename button in task builder, remove superfluous lines in task1.json
Fix whitespace removal for solution test using shlex
Fix wrong textarea height by replacing 0 rows height with 1 row

Also added two class variables to know in the template whether or not to format text monospaced.