Make transition to SGOS easier

[shiromarieke]

To be able to switch from Debian / Tails to Subgraph OS on a daily basis, here are the programs I would need:

• pond
• xmpp-client by agl
• keepassx Could you make sure these are installed or protected by Subgraph?

[mckinney-subgraph]

Added keepassx to the .iso: https://github.com/subgraph/subgraph_desktop_stretch/commit/2d3852e94cb374d50a2df86bd0ab950e06ea5501

[willscott]

pond and xmpp-client are broken out as separate issues.

[xSmurf]

KeepassX has been added. As the other two are referenced in separate tickets (#19 #8) I will close this ticket for now :)