Add default build/install scripts for regular and test builds.

[gskenned]

Add default build/install scripts for regular and test builds.
The purpose is to build directly from unmodified scripts.

Assume the parent folder of osal can have build-osal and local folder trees.
Use relative paths ../build-osal and ../local to build and install.

Suggested scripts: mk-osal-no-test.sh - default build and mk-osal-test.sh - build with test.