doc: Scrubbed ALL sensor library descriptions

In an effort to clean-up and standardize UPM library
documentation, this commit updates (and in most cases,
unifies) the CMake description string AND CXX header
@comname string.

Strings were taken from datasheets when possible, spelling
mistakes were addressed, copy/paste errors where fixed,
Title Case was used, etc.

    * Tested/updated/added @web tags
    * Added/updated invalid sensor images
    * Added/updated @man tags, added missing manufacturers

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/gprs/CMakeLists.txt

@@ -1,5 +1,5 @@
 upm_mixed_module_init (NAME gprs
-    DESCRIPTION "General Packet Radio Service (GPRS) module"
+    DESCRIPTION "General Packet Radio Service (GPRS) Module"
     CPP_HDR gprs.hpp
     CPP_SRC gprs.cxx
     REQUIRES mraa)

src/gprs/gprs.hpp

@@ -48,7 +48,7 @@ namespace upm {
     /**
      * @library gprs
      * @sensor gprs
-     * @comname GPRS Module
+     * @comname General Packet Radio Service (GPRS) Module
      * @altname Grove GPRS Module
      * @type wifi
      * @man seeed