The problem was that the modified ignore pattern was not applied
to the parts of the remote tree we simply retrieve from the db
because the folder etag didn't change.

Even worse, if one removed an ignore pattern, the un-ignored
files would not be synced correctly.

With this change, a modification to the ignore list always results
in a full remote discovery. This guarantees that we find un-ignored
files.

Since we periodically recreatet the QNAM owned by the Account,
the web view could end up holding a dangling pointer to it.

Let the web view use its own QNAM, but make sure that the cookie
jars are shared so that we can grab the session token given
by the server.

Since our DLLs version number aren't bumped, a same file size could
cause a DLL not to be installed to replace an old one.
This eventually can cause a crash of explorer if an incompatible version
of OCUtil.dll is installed alone.

Fix the issue by defining LIBRARY_IGNORE_VERSION. This also makes sure
that installing an old version of the client over a more recent one
if we decide to add version numbers to those DLLs.

This would cause a full sync every 30 seconds.

(cherry picked from commit bacf6166)

This reverts commit e1a36b53.

This reverts commit 1d600cee.

This reverts commit 0f7773ff.

This reverts commit 3df26ef1.

In particular the 'unsupported client version' error message
is now visible to the user when trying to connect to a
server that no longer supports the current client version.