This reverts commit 309f5617.  It
caused password-protected documents to no longer work and made
sc_subsequent_filters_test's testPassword fail.

fix potential bug on short read which has bugged me for a while
where bytes read is always reduced without a check that byte was
read

Nobody ever checked the return value anyway, so just return the string
and use the stream state bits if necessary to find failures.

Doesn't need to be a member, make a standalone function

Rename it to read_zeroTerminated_uInt8s_AsO[U]String, stupid perhaps,
but *shrug*, unambiguous.

Drop misleading overloaded String variants use:
read_zeroTerminated_uInt8s_AsOString or
read_zeroTerminated_uInt8s_AsOUString

added a unit test, valgrinded it, found and fixed invalid read
in original implementation.

This is a cherry-pick of Matúš's e2f30c078fcf26d481c2e90398b450f6c475a483
from the feature/gbuild branch, with the following modifications by
Stephan Bergmann <sbergman@redhat.com>:

* Adapt salhelper/Makefile to what all those Makefiles currently need to
  look like.

* Do not remove salhelper/source/gcc3.map, instead add directly into it
  what otherwise solenv/bin/addsym.awk would add to it on Linux.

* In salhelper/Library_salhelper.mk, add code that on Linux takes care of
  the soname and symbol versioning required for backwards compatibility.
  Solaris would need those features too, and its backwards compatibility
  is thus currently broken.  Also add a bad hack to create the soname
  symlink (xxx.3 -> xxx) in the solver needed on non-Windows platforms (it
  is a bad hack for now in that it e.g. is not removed by "make clean").

* In solenv/gbuild/platform/macosx.mk, add an even worse hack to set the
  correct install name for libuno_salhelpergcc3.dylib.3, with a trailing
  ".3".

Icon by Alexander Wilms

By Alexander Wilms/Stefan Knorr (astron)

Resolved scary "ScToken::GetDoubleRef: virtual dummy called" debug message.

[with large icons]

 - they looks correctly visually, we can make then connector shapes
   once we have new implementation