* Added InputAction::mouseAxisValue
* Added INPUT_UI_SELECT binding for focused GUI widget activation (mouse unbound since mouse clicks are handled differently in menus)
* Added InputManager::accumulateKeyboardEvent(), accumulateMouseButtonEvent(), accumulateMouseAxisEvent(), accumulateJoystickButtonEvent(), and accumulateJoystickAxisEvent()
* Updated secondary INPUT_FIRE keyboard binding to be cursor up key, restoring jam version behaviour
* Updated InputAction::getValue() to return larger of value and mouseAxisValue
* Updated InputManager to process input events and then process InputActions on game tick to prevent lost intra-frame inputs
* Updated CHANGES file to reflect recent work
* Updated README.dm to note that --fps is experimental
* Updated README.dm to note that launch options modify persistent settings
* Updated Game::runMainLoop() to register keyboard, mouse, and joystick event sources, and pass relevant events through to InputManager
* Updated InputManager::processMenuInput() to assign doAction by INPUT_UI_SELECT rather than INPUT_FIRE
* Refactored InputAction::updateState() into processKeyboardEvent(), processMouseEvent(), processJoystickEvent(), and updateValue()
* Refactored InputManager::update() into InputManager::processInput()
* Refactored InputManager::processInput() cancel binding handling into updateBinding()
* Refactored InputManager::processInput() mouse warping code into InputManager::accumulateMouseAxisEvent()
* Refactored InputManager::processMenuInputKeyboard() into InputManager::processMenuInput()
* Refactored InputManager::processGameInputKeyboard() into InputManager::processGameInput()
* Fixed possible memory leak in InputManager::processInput() when grabbing mouse on click