[lib] cleanup some compiler warnings

   - lib/searpc-client.c:353:1: warning: control reaches end of non-void function [-Wreturn-type]
   - lib/searpc-utils.c:93:13: warning: enumeration value 'JSON_ARRAY' not handled in switch [-Wswitch]
[build] add cmake build system

 - fix permission in searpc-codegen
 - remove shared library version