Remove dependency on okularpart from the mobile components

Summary:
This only depended on okularpart due to the export header used in the
kcfgc file, so use a dedicated one for the mobile components that doesn't
export anything.

This enables disabling the part build for mobile-only builds such as
Android, and thus removing the need for some difficult dependencies
like KParts.

Reviewers: aacid

Reviewed By: aacid

Subscribers: aacid, okular-devel

Tags: #okular

Differential Revision: https://phabricator.kde.org/D19037

conf/settings_mobile.kcfgc

@@ -0,0 +1,10 @@
+ClassName=Settings
+NameSpace=Okular
+File=okular.kcfg
+Inherits=SettingsCore
+Mutators=true
+Singleton=true
+Visibility=
+IncludeFiles=settings_core.h
+SourceIncludeFiles=qdom.h,QStandardPaths
+MemberVariables=dpointer

mobile/components/CMakeLists.txt

@@ -20,7 +20,7 @@ set(okular_SRCS
     okularsingleton.cpp
     )
 
-kconfig_add_kcfg_files(okular_SRCS ${CMAKE_SOURCE_DIR}/conf/settings.kcfgc )
+kconfig_add_kcfg_files(okular_SRCS ${CMAKE_SOURCE_DIR}/conf/settings_mobile.kcfgc)
 
 add_library(okularplugin SHARED ${okular_SRCS})
 set_target_properties(okularplugin PROPERTIES COMPILE_DEFINITIONS "okularpart_EXPORTS")

mobile/components/settings.h

@@ -0,0 +1 @@
+#include "settings_mobile.h"