Scale down the Fill button font size and reduce the internal margin if the text is longer. See #52
Scale down the faucet control options text size if it is larger. See #52
Moved the fluid density values and air pressure constants to Constants file.
Refactored watertowermodel.
Minor code refactor and jslint fixes
Removed unwanted code from ControlSlider. Added constructor doc.
Minor code refactor. Added constructor documentation.
Minor code refactor.  Added documentation.