Sourcemap fixes

[ben-ng]

c85d431 fixes an issue minifying backbone.js. There is an off-by-one error when the keys of object literals are quoted strings.

{
   'some': 'thing'
// ^ Uglify says the 'some' token begins on this index, when it really is the next one
}

d051f29 fixes an issue minifying lo-dash.

{
   '\n': 'newline'
//   ^ Sourcemap's "names" array contains a newline character and maps it here
//     when it should be mapping the escaped "\n" string
}

[ben-ng]

e38b5a7 escapes an additional character, found in lodash