Refactor graph_page_data

Remove mean function

Add comments for refactor.

Add more comments

Add more comments, refactor GetMedianRun, and make successfulOnly a required parameter to values.

Add test to graphPageDataTest.php

Add test to graphPageDataTest.php

More documentation

Move GetQuantiles and GetNumeric to graph_page_data.inc

Finish moving GetQuantiles and GetNumeric to graph_page_data.inc

More updates to test

Test pageload data error

Merge some changes from https://github.com/geening/webpagetest/commit/936dba606a072f26b727b3fcbf96bfc0620c842a

Update test load page data

removing test_load_page_data

Code cleanup of graph_page_data.php

Add GetMedianRun test

Fixing code review issues in https://codereview.appspot.com/100870045/

Refactor graph_page_data.php to make it easier to combine multiple tests
onto
one chart.
Show median metric value in addition to median run.
Extract commonly used functionality in page_data.inc into "values" and
"successfulRun" functions.
Fix some typos and add comments.

Remove values corresponding to failed runs from tests -- see differences
at
http://latencylab/graph_page_data.php?test=140529_V9_35C
http://latencylab/graph_page_data.php?test=140530_NR_318
Added an embedded Chrome trace viewer
Added a cache for the processed dev tools requests and page data so we don't keep re-processing the large dev tools files.
Changed 401 response codes (auth challenge) to be treated like redirects
Display the timeline breakdown link whenever we have a dev tools file
wptdriver 177
Merge branch 'master' of github.com:WPO-Foundation/webpagetest
Revert "Added support for reporting timed out page loads for the mobile tests"

This reverts commit 1ebea031b3b447315ac00e81b7c5e7f617b573db.
Fixed the benchmark scatterplot to only display results for successful runs
Merge remote-tracking branch 'upstream/master'
Merge pull request #242 from geening/master

Pull request for graph_page_data refactor
Fixed #248

Added a bunch of (non-sensitive) test information to the testStatus result.
Merge branch 'master' of github.com:WPO-Foundation/webpagetest
Close browser between first and repeat view.

Changed the flow for repeat view tests to close the browser between
first and repeat view (but not clear the cache for the repeat view).

This matches the desktop behavior and is preferred because otherwise the
browser's in-memory cache will be used and it has very different caching
behavior.

BUG=234
R=klm@google.com

Review URL: https://codereview.appspot.com/103130044
remove unused code from CheckImageCompression
Support multiple tests and options for which views and median lines to
show in graph_page_data.php
Make filmstrip view linked to from scatterplot show the correct first/repeat view.
Add check for ./tmp on tmpfs
Fix error in https://codereview.appspot.com/106790043
Merge pull request #250 from rviscomi/img-compression-score

remove unused code from CheckImageCompression