Removing deprecated build.sh script.

Use CMake as specified in README. Fixes #732.
Removing cleanbuild.sh as well.
Merge pull request #743 from rhyolight/remove-build-sh

Removing deprecated build.sh script.
Updated wiki links in README.

Due to changes made in #747.
Merge pull request #748 from rhyolight/update-readme

Updated wiki links in README.
Updated link in CONTRIBUTING.md
Merge pull request #750 from rhyolight/update-readme

Updated link in CONTRIBUTING.md
Adding readme file
Adding content to spatial pooler example readme
Merge pull request #754 from zacg/master

Readme for Spatial Pooler Example