fix "too much recursion" when parsing large bundle

[z8po]

On large css bundle the regexp used in applyTargetTextStyle for parsing css makes firefox hang seconds then throws an "Uncaught InternalError: too much recursion". This fix optimize the regexp by removing useless capture group and replace usefull ones by non capturing group.

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[tomayac]

Thank you, this looks great! Only thing missing is signing the CLA before this can be merged.

[tomayac]

@z8po Friendly ping regarding the CLA signature.