improved alpha channel handling for math ops, removed 'can't substract or divide a color from a number' constraint
color-blending-with-transparency: initial implementation
color-blending-with-transparency: fixed negative result alpha handling (though allowing out-of-range alpha inputs is subject for further discussions/decision)
color-blending-with-transparency: removed debug log statement mistakenly left out
Updated Readme for full examples

Most users and testers would just copy paste the examples. So I added the variables to the small examples itself that it would be testable for anyone.
Minifier complains about annotation in non-JSDoc tag

```INFO: [Minify] Minify: Exception in minifier: input:1665: WARNING - Parse error. Non-JSDoc comment has annotations. Did you mean to start it with '/**'?```
Change American spelling to UK spelling
color-blending-with-transparency: changed func dispatch method from closure to `bind()`
add clean css options parameter and option. fixes #1721
Merge branch 'master' of https://github.com/cloudhead/less.js
move return false to the right place. Fixes #1720
Merge pull request #1717 from joscha/fix-head

Minifier complains about annotation in non-JSDoc tag
Merge pull request #1708 from Swissbite/master

Updated Readme for full examples
Merge branch 'color-ops-fixes' of https://github.com/seven-phases-max/less.js

Conflicts:
	test/less/errors/color-operation-error.txt
add changelog
Merge pull request #1704 from seven-phases-max/color-blending-with-transparency

Color blending functions with transparency.
Merge branch 'master' of https://github.com/cloudhead/less.js
add transparency colour function change to the changelog