[FIX] base: QWeb monetary field rounding

QWeb monetary widget uses the precision of the currency to know the number of
digits to display on a price. The number of digits is based on log10(rounding).
For currency with rounding different than 10^x (e.g. in Switzerland 0.05
to allow 5 cents coins only), the number of displayed digits should be rounded
up. e.g. log10(0.05) is -1.3, rounded up to 2 digits.

Fixes #3233
[FIX] ir_ui_view: Missing separator in search view
[IMP] [FIX] website_blog: better follow mechanism. Now people following
a blog will receive notifications only for published posts. They
will not receive all comments of all posts anymore.
When commenting a post users will receive the answers.

Added tests to try to test this behavior.
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-win32