Fix error in podspec

Merge pull request #40 from twotoasters/readme-updates

Update README with sections for added subspecs

Josh never published 0.7, reverting version number

Update version number to 0.6

upped version number

Add section header for KVO in readme

Update to 0.4

Merge pull request #25 from twotoasters/fix-error-in-podspec

Remove source files lists for subspecs

Merge pull request #24 from twotoasters/upgrade-to-0.3

Prep 0.3 release

Merge pull request #15 from twotoasters/subclass-responsibility

Subclass responsibility