Update .gitignore.
Update .gitignore.

Update the top-level .gitignore to fit the generated files I see on a
GNU/Linux system more closely.

okTurtles/namecoin,cryptostorm/namecoin,jonasbits/namecoin,cfromknecht/namecoin-legacy,Midar/namecoin,rsackler/namecoin,fflo/sixeleven,okTurtles/namecoin,eXcomm/namecoin,namecoin/namecoin,bankonmecoin/namecoin-legacy,namecoin/namecoin-legacy,cryptostorm/namecoin,Midar/namecoin,eXcomm/namecoin,namecoin/namecoin-legacy,namecoin/namecoin,cryptostorm/namecoin,rsackler/namecoin,cryptostorm/namecoin,cfromknecht/namecoin-legacy,cfromknecht/namecoin-legacy,jonasbits/namecoin,fflo/sixeleven,rsackler/namecoin,cryptostorm/namecoin,Midar/namecoin,okTurtles/namecoin,namecoin/namecoin-legacy,jonasbits/namecoin,rsackler/namecoin,okTurtles/namecoin,bankonmecoin/namecoin-legacy,eXcomm/namecoin,cfromknecht/namecoin-legacy,eXcomm/namecoin,Midar/namecoin,okTurtles/namecoin,fflo/sixeleven,bankonmecoin/namecoin-legacy,namecoin/namecoin,namecoin/namecoin-legacy,jonasbits/namecoin,namecoin/namecoin,bankonmecoin/namecoin-legacy,cfromknecht/namecoin-legacy,jonasbits/namecoin,Midar/namecoin,bankonmecoin/namecoin-legacy,eXcomm/namecoin,namecoin/namecoin-legacy,fflo/sixeleven,rsackler/namecoin,namecoin/namecoin