Merge pull request #10 from ChrisBoesch/master

update
Merge pull request #391 from ruijunhuang2010/master

Merge pull request #10 from ChrisBoesch/master
Merge pull request #11 from ChrisBoesch/master

update
Merge pull request #23 from ChrisBoesch/master

update
logic change to the error pop up by selecting date/time
Merge pull request #392 from LI-HE/master

logic change to the error pop up by selecting date/time
Merge pull request #393 from ruijunhuang2010/master

Merge pull request #11 from ChrisBoesch/master
Merge pull request #12 from ChrisBoesch/master

update
date validation for edit challenge
Merge pull request #394 from ruijunhuang2010/master

update
share challenge in profile page
Merge pull request #395 from ruijunhuang2010/master

share challenge in profile page
Adding 2 files for NYP to avoid conflicts
Merge pull request #123 from ChrisBoesch/master

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