better exception stack trace

[larryhe]

Today, i use javascript-ctags to generate javascript tags for a huge project(with hundreds of JS files) and I got below errors, which didn't provide too much useful information to user which files caused this. I spent hours to figure which file caused the problem. As a suggestion, I think it's better to append the source file to the exception stack trace.

/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3872
throw e;
^
Error: Line 1: Unexpected token (
at throwError (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:1156:21)
at throwUnexpected (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:1213:9)
at parseVariableIdentifier (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:2081:13)
at /usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3609:38
at parseFunctionDeclaration (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:2884:14)
at /usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3609:38
at parseSourceElement (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3055:24)
at parseSourceElements (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3095:29)
at parseProgram (/usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3109:19)
at /usr/local/lib/node_modules/javascript-ctags/node_modules/esprima/esprima.js:3609:38