[Libreoffice] [REVIEW] add --backtrace, --strace, and --valgring option to soffice wrapper

Hi,

Kendy suggested to add --backtrace, --strace, and --valgring to the
soffice wrapper. It will make it easier for users to provide the debug
info.

I have realized it in master, see
http://cgit.freedesktop.org/libreoffice/libs-core/commit/?id=dfe7581607e67ced5ff0fce9973b6f2fcd3dee62
http://cgit.freedesktop.org/libreoffice/libs-core/commit/?id=a102b8a093e53366b25a96f959e734bbb4a17d04
http://cgit.freedesktop.org/libreoffice/bootstrap/commit/?id=15a545f7fe0279b26bda96f5bea1d51e5ac5448b

Note that it slightly modifies the current valgrind support:

    + removed --trace-children-skip=*/java option; it is not supported
      by the older valgrind-3.5.0
    + added --num-callers=50 that is suggested at
http://wiki.documentfoundation.org/BugReport#How_to_get_valgrind_log_.28on_Linux.29
    + writing output into valgrind.log instead of stdout; it should be 
      easier for users


Any opinion?
Could I cherry-pick it for the libreoffice-3-4 branch?



Best Regards,
Petr

PS: heh, the second commit in libs-core is ugly; I did all testing in
    the libreoffice-3-4 branch but I decided to push into master;
    I did this mistake when porting to master and resolving
    conflicts