Added sendNewsletter hook
Prevent timing attacks when verifying passwords (see #7115, #5853)
Use `CRYPT_BLOWFISH` as preferred hash algorithm (see #5853)

This effectively raises the minimum PHP version to 5.3.7, because the Blowfish modes that deal with potential high-bit attacks have only been added in this version.
Limit the selectable file types depending on the element type (see #7003)
Fix the new password hash functions as pointed out by @ausi
Make the pagination template more flexible (see #7174)
Merge pull request #7222 from Toflar/feature/sendNewsletter-hook
Show a message if logging in is required to comment (see #7031)