Better package upload error messages

[mcandre]

502 Bad Gateway could be replaced by more specific error messages, encouraging package contributors to improve their formatting.

[nicferrier]

Again, this is something I hope to fix in the new version.

I could do with help there though.

This is the upload:

https://github.com/nicferrier/elmarmalade/blob/master/marmalade-service.el#L150

which calls this:

https://github.com/nicferrier/elmarmalade/blob/master/marmalade-service.el#L121

which makes a temp file and puts the package data in it and then uses this to get the package path:

https://github.com/nicferrier/elmarmalade/blob/master/marmalade-service.el#L121

which uses this to get the meta data of the existing (temp) package file:

https://github.com/nicferrier/elmarmalade/blob/master/marmalade-service.el#L67

and that, I think, is where a lot of error checking needs to be done and reported from.

[nicferrier]

pretty much done.

of course 24.4 breaks it all over again. sigh.