New "getting started" and reorganization of README.md

~ Reorganized to put important information at the top
+ Added more information about dependencies and repositories
+ Added a "getting started" section with information on Maven
~ Revised initial "about jwbf"-type statement with more detail
    and reason to use jwbf
- Removed design goals; these will be added to developerDocs
~ Clarifications in Getting started and Dependencies
+ Added table of contents with internal links
- Removed Scala section (may add it to developerDoc.md)
~ Miscellaneous rewording, typo fixes, etc.
~ Simplified some wording
~ Readability tweaks

Task: #26