Download.rvcurve requires user to omit "HD"

[bjfultn]

The RV CSV files have the "HD" removed from their name. If the user does not know this and simply asks to download the rvcurve for "HD185144" (for example) it will download a file which contains only an error message. The user must instead request the rvcurve for "185144".

[bjfultn]

@JohnGood I'd like to fix this issue if possible before passing it out to CPS test users. Is this reasonable to fix in a couple days? I think this needs to happen in the idlDriver C code, but if it can be fixed at a higher level in the Python interface I'm happy to work on it myself.

[bjfultn]

@JohnGood bump on this issue while you are in there in the next couple weeks.

[bjfultn]

This is actually no longer the case. Still lets go ahead and strip off leading HD's everywhere so that the other IDL commands are consistent with the TARGET column in the DB.

[JohnGood]

I hesitate to update this right away for two reasons: Existing databases will then be wrong (though this may only affect you) and the documentation also needs to be updated. Let's promote all these changes as soon as they are all done.