allow less files to have query paramaters. Fixes #788
lessc: Defend against missing output directories

If an output specifies a destination inside a directory that doesn't exist, it blows up unceremoniously. Let's avoid that.

Also, uses modern fs.writeFileSync instead of manual open/write/closeSync.
Back-compat for existsSync in directory check

fs.existsSync was added in 0.6, and path.existsSync was added in 0.4.2:

http://nodejs.org/docs/v0.4.2/api/path.html#path.existsSync
Log output file written when verbose.

This helps CI builds keep a record of exactly what happened, among other things.
Create CONTRIBUTING.md
Update CONTRIBUTING.md
Add initial browser test suite using phantomjs for headless testing and jasmine
Add browser specific url tests
bad error message trying to assign @@var. Fixes #1077
parser.imports passing errors

parser.imports stored any errors in .error, but only returned an error to the callback on that last import in the queue.

This commit makes it return the stored error (that.error).

issue #463
Function "modifyVars" added

The function "modifyVars" the option to modify variables in the
less-file without reloading less-file, including potential
import-files declared with "@import".
unbundle css min. Add optional dependency on ycssmin. Correct some things in the package.json. Add a .npmignore. Fixes #1080
Update CONTRIBUTING.md

add developing information
Test that import paths load from the current directory first
Look in the current directory last when looking for imports. Fixes #1083
make import-once use the full path, not the possibly relative path to determine if an import has already been included
Make import-once fix, but for the browser
Fix comment chunking. Fixes #1082
support for `@import` linking to .less files over HTTP
tidy code up, change to callback errors instead of system exit