encapsulated parameters of drawLedger

also added hook tags for the Ledger on the main page.
Hooks could be dynamicaly added as needed to hang widgets off of in the
future.
now redraws the ledger within its  hook

redrawn datepickers still broken. Dynamicaly added class "has datepicker"
not re-added.
fixed readdign datepicker ability after ledger reload

the initial datepicker jquery-ui functions had to be re-run on the text
elements.
fixed size of ledger height and gave it scrollbars

now the ledger itself takes up one screen. There will be double scrollbars
(one for the leger, one for the browser) once other widgets are added, and
I;m not sure if that's a good idea. The alternative it the date range
dictates the length of the page, possibly pushing widgets above and below
the ledger far apart. I will have to make more widgets before this can be
determined.

For now it works, as the range selector sub-widget stays in place.