So far the backend libraries' include paths were relative within this
repository. This means the header files could not be used at their
installed location.
This change replaces them with "<>" includes to fix that problem and adds
a new include directory so building everything at once still works.
With this change it should be easier to actually split some parts into
another repository if this one would become too big.
* Rely not only on the FolderErrors event
* Request pull errors when opening the dialog
* Use "pullErrors" from FolderSummary
* Move code for directory error dialog into
its own class
This should fix that sometimes obsolete errors
were still displayed or actually present errors
missing.
Martchus