SCViewResult options, improve ShowResultAfterRun

1) Option `SingleCompileRun_split` allows for vertical splits
2) Rename `g:SingleCompile_resultheight` to use it as width for vertical splits
3) Create a mapping to make it easier to close the result window
4) Substitute `exec "g/.*/d"`, as it interferes with 'hlsearch', i.e., if 'hlsearch' is set all the text on the result window is highlighted and the previous search is replaced.
5) When the  g:SingleCompile_showresultafterrun option is active:
* Do not show the regular output on successful runs
* Close the result windows when compilation fails