mask old versions (before 1.1.4) for removal

1.1.2 and 1.1.3 are broken and should not be used

ebuilds before 1.1.4 don't support systems using python3 as default
python version (build fails) and will be removed as those versions
are deprecated anyway

ebuild pdftools-0.37 also doesn't support systems using python3 as
default python version (build fails) and has been replaced by
pdftools-0.37-r1