UploadWizard/Funnel analysis

This is an explanatory page for the funnel analysis of UploadWizard. The graphs of this analysis illustrate the number and/or percentage of users who drop out at each step of the UploadWizard. We are tracking this as a means of understanding where failure is occurring, so that we can prioritize fixes that need to be made.

Ordered list of steps as experienced by end users
 * 1) tutorial - the Puzzly licensing tutorial
 * 2) file - the actual file upload step
 * 3) deeds - the selection of license information
 * 4) details - long form to input many details about each file uploaded

Known issues
 * Substantive issue: huge dropoff at the file stage is steep (71.2% as of 2014-09-18). Steps are underway both to better understand this (see card #862 and card #903), and fixing one problem that we believe could be a large contributor (see Bug 46741).
 * The absolute number of people getting to the file step seems to be higher than the tutorial step. This doesn't make sense, since the tutorial step is the first step, and the logging code already takes into account that some people have a preference set to skip the tutorial.  This is also the cause of the tutorial percentage exceeding 100% in the third graph
 * Between 2014-09-12 and 2014-09-18, no data was collected due to a bug in the logging code due to a configuration error.

Event logging schemas:
 * meta:Schema:UploadWizardStep
 * meta:Schema:UploadWizardFlowEvent
 * meta:Schema:UploadWizardErrorFlowEvent