Standardize build output naming.

Build output changes are as follows:

    spf.js  ->  spf.js
    debug-spf.js  ->  spf-debug.js
    tracing-spf.js  -> spf-trace.js
    bootloader.js  ->  boot.js
    debug-bootloader.js  ->  boot-debug.js
    tracing-bootloader.js  ->  boot-trace.js

Closes #18.