Web-Based Wallet GUI RC3

Adds a web-based GUI module that is loaded in with the u modules parameter. When enabled it is accessed on localhost at the same port that the wallet API is set up for; by default this is http://localhost:4280. All sensitive interaction with the wallet GUI requires the user to also supply their session ID (which they are assigned after supplying a valid wallet password) to protect the user from accidentally compromising their seed, password, or coins.

All static resource files are stored in the ./node/api/resources/ directory which should make it easy to adjust graphics and css styling in the future.

Adds a downloader module that is loaded with the d modules parameter. When enabled and the wallet has no consensus the downloader module will download the bootstrap consensus from scpri.me before loading the consensus module.

Adds a scp-ui package that behaves as a native application. The Makefile, build scripts, and release scripts have all been updated to compile the scp-ui application.