Merge pull request #1 from stelzzz/patch-1

Update currencies/management/commands/initcurrencies.py
Update INSTALL.txt

how to install latest version from Git
Add convert multicurrency function

Example of use:
price=convert(100, "RUB", "UAH")
Convert 100 Russian Rubles to Ukrainian Hryvnia (via base USD currency)
Update README.md
Update currencies/utils.py
Update currencies/templatetags/currency.py

add "currencuy_convert" template tag
Merge branch 'master' of https://github.com/stelzzz/django-currencies
Remove git install instructions as they don't point to the right repo
Name the template tag for conversion correctly, and some PEP8 tidy ups