Modified   test/scratch.rb

Deleted some '^M's.
Improved some rspec files

Replaced be_true matchers to be_[predicate] matchers
Brushed up src/FormalSum.rb and some spec files

Let the method << be protected and add a test for this to
test/FormalSum_spec.rb.
Modified almost all spec files not to repeat "describe CLASSNAME".
Moved codes for Magnus expansion to a new project
Modified src/LieBracket.rb
Added test/OLD to the .gitignore file
Modified .gitignore

Resolved the duplication of ".orig"
Merge branch 'experimental' of https://github.com/yamryo/GLA