Added pdb support (borrowed code from Gallina's python.el).
Added sage-shell:-delete-output.
Fixed sage-shell-edit:exec-cmd-internal.
Fix the bug that the point does not move to the process-mark after
sending command? or command?? to the process sometimes.
Force updating the mode line when sending.
Select win when sending a command.
Added sage_tex_load.
Added sage-shell:add-to-texinputs-p.
Run sage-shell:output-filter-finished-hook at the last of filter function.
Fixed sage-shell-help:file-type-make-button.
Modified sage-shell:send-blank-line.
Added commentary.
Add an optional argument recenter-arg to sage-shell-help:file-type-make-button.
Fixed code that adds a path to TEXINPUTS.