Shortcut for preview-insert

[Andrew Parsloe]

Dear developers,

I notice that the shortcut Ctrl+P is not used as a shortcut anymore. If 
I remember correctly it was used when LyX supported direct printing of 
the LyX file. I suggest that it be bound to preview-insert which 
currently has no shortcut. With this binding, a couple of quick taps of 
the keys, Ctrl+P Ctrl+L inserts an ERT inset inside a preview inset with 
the cursor waiting inside the ERT inset. Type your latex code, move the 
cursor outside and preview does its magic. (The actual typing sequence 
is: hold down the Ctrl key, then tap P L which are diagonally adjacent 
keys on a qwerty keyboard. It's very convenient.)

Andrew