jvmfwk: generalize (and fix) the do_msvcr71_magic to Oracle JRE 7

With just the Oracle JRE installed, it is not possible to load the
"jvm.dll" directly, because the required MSVC runtime DLL is not
found (unless some other software happens to install it system-wide),
as described in http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7184978

There was a hack "do_msvcr71_magic" to manually load the runtime that
is bundled with Oracle JRE 6 and this generalizes that to work with the
MSVCR100.DLL that is bundled with Oracle JRE 7 as well.

An additional adaption of the virtual addresses in the file is done,
and it's a mystery whether it even worked before without that.

This issue was not user-visible before because LO releases 3.5 - 4.2
bundle the MSVCR100.DLL themselves.

Change-Id: If61565df80ff8a68472a76000ab5b10d6c78e11c