added guide for building the client
Update README.md

fixed markdown
Merge pull request #8 from georgkrause/master

building guide
fix: catch any failure to initialize the lib
Merge branch 'zuckschwerdt-libfail'
Qt multimedia is needed with official branding only (use qmake "CONFIG+=branding")
Merge branch 'zuckschwerdt-fix-branding'
fix: accessing a first list element on lists crashes
Merge branch 'zuckschwerdt-fix-crash-empty-addressbook'