Create libcdr.rb

This formula is still incomplete.
Just wanting to see if it passes brewbot test.
Reference issue: https://github.com/Homebrew/homebrew/issues/30383
Update libcdr.rb

updated changes specified by mistydemeo (https://github.com/Homebrew/homebrew/pull/31162#discussion_r15440749)
Update libcdr.rb

removed trailing whitespaces as per brew audit
Update libcdr.rb

cleaned up formula. lets submit it this way and if it needs to be improved then return to it
Update libcdr.rb

Got the test to work with the library co-creator @dtardon
Update libcdr.rb

removed extraneous test code as per suggestion by library co-creator @dtardon
Update libcdr.rb

don't know how whitespaces crept in there. sorry
Update libcdr.rb

this is in c++ so changed to ENV.cxx as per @dtardon
Also is this Kosher?  "-I#{HOMEBREW_PREFIX}/include/libcdr-0.1" or is there a better way ?
libcdr: add 0.1.0 bottle.