Allow individual action to set restart, using RESTART=YES or
RESTART=NO. By default, RESTART=AUTO, that means that global
restart settings are used.

Notice that this required to change the way OFile knows about
restart. Indeed, if the file is linked to an action,
it should use Action::getRestart instead of PlumedMain::getRestart.

They were giving warnings with cppcheck

repeated assignment

initialization list

check for empty container

[almost]

[almost]

In commit f4ac1cf2 I forgot to also change plumed.dat.0 file.
I fix this now, so as to decrease mismatches in regtests

[makedoc]

close #124

[makedoc]

closes #123

tutorials: fixes

@gtribello please check before I merge!

This highlights bug #123

I suspect a problem in v2.1 with DRMSD cutoff.

This test is working properly in v2.0

[makedoc]

Conflicts:
	VERSION

(suggested by Richard Cunha)

[makedoc]

(hopefully solve a problem with belfast-8 not showing properly)

[makedoc]

I fixed changlog CHANGES/v2.0.txt since it was not properly
showing (probably doxygen 1.8.6 could interpret it correctly)

[makedoc]