global: push to FTP server

* Pushes the output files of PoS, APS and CONSYN
  to a FTP server.

* Adds the location of the uploaded files on
  the reporting email.

* Refactors imports.

Signed-off-by: Georgios Papoutsakis<georgios.papoutsakis@cern.ch>
BibTasklets: APS harvest reloaded

* Refactors the bibtasklet code and migrates lots
  of functionality away from the tasklet and into the apsharvest
  module instead.

* Adds new modules in apsharvest to keep custom errors contained
  as well as refactoring tasklet code into an OO paradigm in
  apsharvest_engine.

* Adds any FTP uploaded files to summary e-mail.

* Updates FTP API in apsharvest_utils by squashing two functions together.

* Improves the documentation in the bst_apsharvest script.

* Makes the final results filename more readable by including the
  dates harvested (if available) or the current date in the name.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
BibTasklets: set threshold date to from_date

* Sets the threshold date for harvesting APS records
  automatically to the from_date value.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
installation: truncate virtual indexes

* For new installations, disable the virtual index definitions.
  Will be re-activated after fully moving to virtual indexes.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
BibFormat: rename hepdata to data

* Renames 'hepdata' to 'data' in a link