This is a huge commit, applying indentation to the whole
code. Notice that this commit is made on master branch
after having merged with -s ours from branch v2.3

See #215

This is a huge commit, applying indentation to the whole
code.

See #215

I added a script located in src that applies astyle to
all source files and add them to git. This script can
be invoked as `make astyle`.

File .astyle.options contains the astyle command line options

See #215

I added a full copy of astyle 3.0 to the plumed repository.
This is allowed by astyle license.

See #215

Take advantage of https://github.com/GiovanniBussi/macports-ci

In this manner I will have to maintain a single script even though
I use macports on travis-ci for multiple projects

Prior to this change a misuse of the LOWMEM keyword could cause segfaults.
Now these cases crash with an error.