- Provide and obsolete all the gtk3 disabled stuff if we disable
gtk3 to ease migration

- Drop patch libreoffice-lto-failtest.patch as the problem was with
memcpy in wrong phases, fixed by cflag -flifetime-dse=1

- Provide and obsolete also libreoffice-branding-SLE

- Use pkgconfig(libpg) instead of posgresql-devel dependency

- Bring back offline help per popular demand as lto saves space
we could use with it bsc#915996
- Update patch to not call python directly during help generating:
* 0001-Use-PYTHON_FOR_BUILD-instead-of-calling-python-direc.patch

- Use gpg keys to verify downloaded archives

- Add patch to disable test failing with LTO:
* libreoffice-lto-failtest.patch

- Switch to memory-constraints macros to limit threads as needed
- Enable LTO on libreoffice, 16% smaller binaries, less memory used