warn that in-place ln_s import can be slower

see https://trac.openmicroscopy.org.uk/ome/ticket/12217
The password reset command was missing.

Note I'm not sure if this is still correct for the new salted passwords.
Rewrite the password reset instructions

Removed old openssl commands
Add additional Windows requirements.
Merge pull request #797 from ximenesuk/rebase/develop/add-windows-options

Add DropBox Windows requirements
Merge pull request #786 from mtbc/rebased/develop/in-place-warning

warn that in-place ln_s can be slower for HCS (rebased from dev_5_0)
Merge pull request #795 from manics/rebased/develop/root_password_reset

Root password reset command (rebased onto develop)