Fixed a bug, there is a test should fail if the original

this pull request change maxBuffer 200KB to 1MB, and check "exitCode !== 1" to "exitCode === 0" about exec.ts and runner.ts .

http://nodejs.org/api/child_process.html#child_process_child_process_exec_command_options_callback
require("child_process").exec in Node.js, this spec wrote
> maxBuffer specifies the largest amount of data allowed on stdout or stderr - if this value is exceeded then the child process is killed.
and default values are 
> maxBuffer Number (Default: 200*1024)

exec this command.
$ node _infrastructure/tests/typescript/tsc.js --noImplicitAny threejs/three-tests.ts 2>&1 > /dev/null | wc
1963 21628 291809
stderr wrote over 200KB, because exitCode === undefined

I'm sorry to tried fix the underscore.string/underscore.string-tests.ts, but I gave up. It still raise compile error.