It was discovered that on a Russian Windows, by default only Russian and
German dictionaries would be installed, but no English dictionary.  This is
because since e2fac988 "fdo#53009: For msi
installer, only default-select a subset of dictionaries" only those dictionaries
mentioned in setup_native/source/packinfo/spellchecker_selection.txt were
default-selected, but it apparently was a misunderstanding that
spellcheker_selection.txt for many locales does not list "en" even though an
English dictionary should always be default-installed.

Quoting Andras Timar <atimar@suse.com>:  "AFAIK en-US localization with English
dictionaries is always installed in all 3 supported platforms by default.  On
Windows default install should always select en-US and English dictionaries.  If
it does not do so under certain circumstances, then it is a bug in my opinion.
We removed en-US entry from the spellchecker selection file for this very
reason.  It would have only bloated Mac and Linux langpacks."

So this fix simply makes sure that "en" is included in every line of the
generated spellchecker_selection.hxx that is used by
setup_native/source/win32/customactions/sellang/sellang.cxx to determine which
dictionaries to select by default.

Change-Id: I3db68585dc6269a7db2f6cbf6b79796dc09d05e8