Add namespace to all PlatformIO library references (#2296)

* Remove unnecessary duplication in platformio.ini

* Add namespace to all platformio library references

* Add cmake-build-* to gitignore

They're generated by the CLion add-on for each PlatformIO environment.
Listing them all separately seems nonsensical.

.gitignore

@@ -102,10 +102,7 @@ CMakeLists.txt
 .idea/**/dynamic.xml
 
 # CMake
-cmake-build-debug/
-cmake-build-livingroom8266/
-cmake-build-livingroom32/
-cmake-build-release/
+cmake-build-*/
 
 CMakeCache.txt
 CMakeFiles