Convert grive to a pure shared library

In this way it's possible to develop independent clients, sharing
the same "functional" part.

CMakeLists.txt

@@ -8,7 +8,19 @@ include_directories(
 	${grive_SOURCE_DIR}/src
 )
 
-add_executable( grive
+file(GLOB DRIVE_HEADERS
+    ${grive_SOURCE_DIR}/src/drive/*.hh
+)
+
+file (GLOB PROTOCOL_HEADERS
+    ${grive_SOURCE_DIR}/src/protocol/*.hh
+)
+
+file (GLOB UTIL_HEADERS
+    ${grive_SOURCE_DIR}/src/util/*.hh
+)
+
+add_library( grive SHARED
 	src/main.cc
 	src/drive/Collection.cc
 	src/drive/Drive.cc
@@ -21,12 +33,24 @@ add_executable( grive
 	src/util/OS.cc
 )
 
+add_executable( grive_cli
+	src/main.cc
+)
+
 target_link_libraries( grive
 	curl
 	json
 	${OPENSSL_LIBRARIES}
 )
 
+target_link_libraries( grive_cli
+    grive
+)
+
+set_target_properties(grive PROPERTIES
+    SOVERSION 0 VERSION 0.0.1
+)
+
 add_executable( unittest
 	test/UnitTest.cc
 	src/util/DateTime.cc
@@ -37,3 +61,11 @@ add_executable( unittest
 target_link_libraries( unittest
 	cppunit
 )
+
+
+## Install targets
+install(TARGETS grive LIBRARY DESTINATION lib)
+install(TARGETS grive_cli RUNTIME DESTINATION bin)
+install(FILES ${DRIVE_HEADERS} DESTINATION include/grive/drive)
+install(FILES ${PROTOCOL_HEADERS} DESTINATION include/grive/protocol)
+install(FILES ${UTIL_HEADERS} DESTINATION include/grive/util)