Fix indentation in clean utility

utils.clean extracts a test method content re-indenting the function for whitespaces.
This commit fixes to issues with indentation

* windows line feed `\r\n`
* tab indentation `\t`
Return true from window.onerror handler

Mocha's own error reporter will report the error; it shouldn't
be printed to the console, trigger an error badge on the Firebug
toolbar button, etc.
Expose only the specified UI in the browser

When instantiated in the browser, Mocha registers the "BDD-style"
interface. Since an explicit call to the browser-specific `mocha.ui` is
required, the original registration is invalid. Prevent that UI from
reacting to the `pre-require` event (and exposing its API).
introduced mocha.throwError for better async error handling
Removed duplicate test output for multi-line specs
Fix for NaN coming in time attribute when test fails.
add Runnable.globals(arr) method for per test global whitelist

Instead of suite wide whitelisting of global leaks, this allows for
individual tests to whitelist globals. This allows for keeping global
detection for tests which are not expected to set globals while allowing
for certain globals if the author expects a test to set globals
Handle errors in hooks (#1043)

Only suites affected by a failing hook will stop.
Merge branch 'Rulikkk-hook-error-handling'

* Rulikkk-hook-error-handling:
  Handle errors in hooks (#1043)
Update history.md for #1043
Release 1.15.0
Update mocha.js
Release 1.15.1
Update history.md
Ensure process exit code is preserved when using --no-exit
Merge pull request #1039 from vnikiti/xunit-sonar-fix

Fix for NaN coming in time attribute when test fails.

* vnikiti/xunit-sonar-fix:
  Fix for NaN coming in time attribute when test fails.
Remove the spinner when using --watch (fix #806)
Merge pull request #1059 from glenjamin/master

Ensure process exit code is preserved when using --no-exit
Merge pull request #1046 from defunctzombie/per-test-globals

add Runnable.globals(arr) method for per test global whitelist
Merge pull request #984 from jugglinmike/browser-ui

Expose only the specified UI in the browser

* jugglinmike/browser-ui:
  Expose only the specified UI in the browser