@gtribello I have to revert this since it fails on travis.
Can you please fix it and add it again on v2.4 (then merge, as you did)?

Thanks!

This reverts commit ce4bbf4e.

Check that METAD + TARGET + GRID_SPARSE works correctly.

@chi2, @chi3, @chi4 and @chi5

* restyling for the reweighting c(t) calculation

* fixed bug in multidimensional grid integration

* fixed regtest for 2D reweighting

* changed reweighting keywords and some doc

See #399

I changed Plumed::invalid() to Plumed::makeInvalid() and added a new function
Plumed::makeValid(). These names are more inline with stdlib names
(e.g. make_shared), though with our conventions for capitalization.

Hopefully there's no code yet using this (beta) interface.

In addition, I made it possible to use a macro to change the behavior
of the default constructor to makeInvalid(). This might be
useful in python wrappers to avoid opening the library twice
(python objects always use the "nullary" - default - constructor first).

This bug was reported by Carol Simoes and fixed by Javi Iglesias.

The fix requires resetting a regtest.

* Added Cosinus SwitchingFunction

* fixed astyle

* regtest cosinus switching function

When using the C++ interface, this change remaps exception within plumed
to a class that inherits from std::runtime_error.
This allows them to be catched also from an MD code linked to
a different C++ library.

I also removed some cpp options, I think it is better to enforce
exceptions to be managed in this way.

Returned argument should be last.

* flying Gaussian added

* Update MetaD.cpp

Making plumedcheck happy

* Update MetaD.cpp

Making plumedcheck happy again

* Update MetaD.cpp

Making plumedcheck finally happy

* regtest for flying Gaussian

* Update MetaD.cpp

Adding flying Gaussian with parallel tempering.

* Update MetaD.cpp

* Flying Gaussian with Parallel tempering

* Added PT to FG

* PT for FG

* PT for FG

* PT for FG

* pokus

* Making patch to know from plumed.dat

* Make patch know from plumed.dat

* Make patch know from plumed.dat

* Make patch to know from plumed.dat

* Update GREX.cpp

* Update GREX.cpp

* Update PlumedMain.h

* Update GREX.cpp

* Update GREX.cpp

* Update GREX.cpp

* Update repl_ex.cpp

* PTFG

* oprava

* blbost

* blbost2

* flying gaussian with parallel tempering

* PTFG

* just Flying Gaussian without PT

* just Flying Gaussian without PT 2

- Added many points to rt-lepton test
- Added nandelta() function
- Made definitions of delta(0) and step(0) equal to matheval

Works both with and without ASMJIT

* copying and adapting the FaMetaD code from the old version, still need to be tested

* forgot keywords

* fixed a few things in the FaMetaD

* improved parsing, error msg, and log printing

* moved updating of pace to update()

* astyle fix

* made FaMetaD work with current acc cacluations

* regtest for FaMetaD

* added printout of reading in of acc value

* fixed a newline error in acc printout

* added manual info for FaMetaD

* astyle fix

* removed not needed values from colvar file in rt

* fixed a problem with restarting of FaMetaD

* added rt for restarting of FaMetaD

* add notes to the manual on restarting and acc factor

* fix for restart regtest for fametad

* added warning if restarting and not reading in acc from file

* astyle fixes

* Added a check to make sure that combing FaMetaD and MPI mwalkers is not allowed

* changed error call to be consistent

all -> allatoms
physical -> mdatoms
virtual removed

See https://github.com/plumed/plumed2/pull/372