Utils.js cleanup

For utils.js to shine even brighter - most of the changes are extremely minor, so there is a single pull request with 3 small commits
1. converted it to work in strict mode, fixed absent `var`, satisfied jshint
2. cleaned up unused code - around the whole system only `trim` was used. it should be easier to add other trims or use specific lib than keep bloated code
3. instead of silent try/catch now 'if' is used - confirmed and worked both on node and browser