[libsigcplusplus] (13 commits) ...cmake: reduce required version to 3.2

[Marcin Kolny <mkolny src gnome org>]

Summary of changes:

  f5133ac... cmake: init - add cmake files (*)
  a7cdbb9... cmake: add pkg-config support (*)
  d5b8ffd... cmake: generate cmake *Config and *ConfigVersion files (*)
  7f7170e... cmake: generate and install uninstalled.pc file (*)
  5e7a8f8... cmake: install headers from sigc++ directory (*)
  0e5614f... cmake: add uninstall target (*)
  be837a6... cmake: don't install uninstalled.pc file (*)
  b4ecce0... cmake: install sigc++config.h file (*)
  6b190c9... cmake: fix library output name (*)
  4b63f8c... cmake: fix library name (*)
  f4565d8... cmake: fix generating cmake *Config files (*)
  b0aee16... cmake: add cmake files to dist package (*)
  0ec1b06... cmake: reduce required version to 3.2 (*)

(*) This commit already existed in another branch; no separate mail sent