Added new contributor.
Merge pull request #4 from MattBlack85/trykuba

Added new contributor.
Added dutch translations for invoices status.
Made a more generic function to send efax or email.
function to send efax is very very similar to fucntion to send mail,
the difference is the address you send the mail from and the body/attachment.
All the rest is exaclty the same, so to avoid duplicate function we add a variable
to the orignal funtion that will tell the server if we are try to send an email
or an efax.
Removed not needed language choices.
Added language choices for NL and BE items (Dutch language for both).
Set the correct choices that will be passed to template for IT and NL language.
The function accepts now one additional argument (type).
Redisigned draft function.
Now depending of what object we want to generate (mail or letter)
the function will behave differently. If we want to send a mail
the way will be the same as before, if we want to send a letter we
try to generate a PDF file.
Added utf-8 coding to avoid error when using local characters.
Imported additional modules we need to generate PDFs.
Added Vendor class as imported module.
We need acces to that class to find data related to vendors.
Styling as code must be clean and follow the python way.
Indentation fix.
Added a new field to the model.
Added bootstrap class to invoicedate element before template rendering.
Added the new field into the form. Also changed the last form before vendor section to avoid problems when adding dinamically new invoices.
Changed behaviour on ajax success.
Now if we got answer "no mail in our db" the text is placed as placeholder
rather than text.
Added the new field invoicedate to dynamic form construction.
When Add is clicked the standard operations for other fields are made on our
fresh added field.
Merge pull request #6 from MattBlack85/add_invdate_column

Added invoicedate column to model and updated all relative JS/HTML needed.