added a check to see if node.source is defined
Merge pull request #122 from josiahsavary/121

added a check to see if node.source is defined
Add tests for nodes without source
Add tokenizer
Add errors tests to tokenizer
Better tests for tokenizer
Add content value to all tokens
Do not split space tokens
Add end position for word tokens
Add brackets token
Split word tokens by ! symbol
New parser based on tokens
Allow to parse mix of decls in rules
Use Safe mode only for BrowserHacks integration test
More readable non-name ID
PreviousMap now works with CSS string
Detect map before parsing
Detect from input file name by prev map
Use from option as default to option
Fix missed ;