This adds some source files, a script and skeleton for building
a Debian package that installs the zcash daemon and CLI tool.
Also removes unused Bitcoin files.
Move from sourceforge to linux foundation.
Also get rid of some other stale mentions of sourceforge.
Github-Pull: #6319
Rebased-From: 88d8525ca2ff2afc171cd0f625a098371f3a6af5
Use a series of .png frames for the spinner instead of a .mng.
`mng` is an obscure image format and is not built by default into Qt5.
This appears to improve the crispness of the spinner as well.
Does not noticably increase the size (still ~27k) and the code
is not more complicated either.
- icon from the LGPL Nuvola set (like the tick) - http://www.icon-king.com/projects/nuvola/
- include 'boost/version.hpp' in db.cpp so that the overwrite version of copy can be used
- catch exceptions in BackupWallet (e.g. filesystem_error thrown when trying to overwrite without the overwrite flag set)
- include db.h in walletmodel.cpp for BackupWallet function
- updated doc/assets-attribution.txt and contrib/debian/copyright with copyright info for new icon