kauri-forms-sample: upload control sample

[karel]

• no about page
• Why is dbmockpath variable set?
• sample is missing valuable information: how to set it all up? Wiring? Spring?

[karel]

• The about page was added some time in the past.
• The dbmockpath variable is not needed, it was copy-pasted from an other sample.
• I have updated the online documentation for the upload control ​http://docs.outerthought.org/kauri-docs-current/217-kauri/363-kauri/g2/401-kauri.html and added a pointer in the sample. I'll commit this in the near future

[karel]

In [1829]:

Added pointer to the (updated) upload control documentation.

fixes #415