Update build-unix.md
Update build-unix.md

Added some n00b install assistance building on Debian requirements
Earlz/dobbscoin-source,Earlz/dobbscoin-source,Earlz/dobbscoin-source,dobbscoin/dobbscoin-source,Earlz/dobbscoin-source,Earlz/dobbscoin-source,dobbscoin/dobbscoin-source,Earlz/dobbscoin-source,dobbscoin/dobbscoin-source,dobbscoin/dobbscoin-source,dobbscoin/dobbscoin-source,dobbscoin/dobbscoin-source