qt: Install SpecialJob

* lang/qt/src/Makefile.am: Install SpecialJob
* NEWS: mention it.

--
SpecialJob was and is public API. So it needs to be installed.

NEWS

@@ -17,6 +17,7 @@ Noteworthy changes in version 1.7.1 (unreleased) [C26/A15/R_]
  WksPublishJob::startRecieve     REMOVED.
  MultiDeleteJob                  NEW.
  AbstractImportJob               NEW.
+ SpecialJob                      NEW.
 
  * cpp Interface changes relative to the 1.7.0 release:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

lang/qt/src/Makefile.am

@@ -57,6 +57,7 @@ qgpgme_headers= \
     protocol.h \
     qgpgme_export.h \
     qgpgmenewcryptoconfig.h \
+    specialjob.h \
     signjob.h \
     signkeyjob.h \
     signencryptjob.h \
@@ -91,6 +92,7 @@ camelcase_headers= \
     MultiDeleteJob \
     Protocol \
     QGpgMENewCryptoConfig \
+    SpecialJob \
     SignJob \
     SignKeyJob \
     SignEncryptJob \
@@ -138,7 +140,6 @@ private_qgpgme_headers = \
     qgpgmekeyformailboxjob.h \
     qgpgmewkspublishjob.h \
     qgpgmetofupolicyjob.h \
-    specialjob.h \
     threadedjobmixin.h
 
 qgpgme_moc_sources = \