Move actions' part into dedicated subroutines

Currently, both supported actions ("create-config" and "backup") were either in
a big "if" or directly inline, thus not clearly delimited.
If I want to add more actions this has to be cleaned

This fix moves the "create-config" into a "actionCreateConfig" subroutine and
the whole "backup" part into it's own "actionBackup" subroutine.

Some script-related part have been moved to subroutine too:
* configuration file loading is now done by "loadConfiguration"
* preparation of statuses is now done by "prepareStatuses"

Handling of main action is now nicely done by a simple switch/case where adding
a new action simply means adding a new case.
Merge branch 'review/actions_into_sub'
Removes old, unused, start time code
Removes trailing spaces
Adds the "list-storages-locations" action

Not implemented until now, this action returns the URL to give to duplicity when
accessing storages with duplicity actions such as verify and list-current-files.
Increments version to 0.1.6.
Refactorize service's subdir path logic into getServiceSubdirOnStorage()

Logic to get the subdirectory path for a service was inside
executeDuplicityPathBackup() and could not be used from outside. This commit
allow other parts to use that logic.
Cleans some LDAP DN before being used as path (replaces ":" and "/")

The config-specified DN trees were used as is for path even when they contained
":" or "/" which have some special significations.
Removing theses characters seems wiser.
Refactorizes logic of where to dump an LDAP DN

Logic to determine where to store an LDAP DN tree dump was inside
service_ldap_dumpDnTree() and could not be used from outside. This commit moves
it to service_ldap_getDumpFilepath() thus allowing other parts to use that logic.
Refactorizes logic of determining which MySQL databases have to be dumped

Logic to building the list of MySQL databases that are to be dumped was
inside backupMysql() and could not be used from outside. This commit moves
it to service_mysql_getDatabasesToDump thus allowing other parts to use
that logic.
Refactorizes logic of where to dump a MySQL database

Logic to determine where to store a MySQL database dump was inside
service_mysql_dumpDatabase() and could not be used from outside. This commit
moves it to service_mysql_getDumpFilepath() thus allowing other parts to use
that logic.
Refactorizes logic of determining which FS paths have to be backuped

Logic to building the list of path that are to be backuped for a FS service
was inside backupFs() and could not be used from outside. This commit moves
it to service_fs_getPathsToBackup() thus allowing other parts to use that
logic.
Refactorizes logic of determining which LDAP DN trees have to be backuped

Logic to building the list of DN trees that are to be backuped for an LDAP
service was inside backupLdap() and could not be used from outside. This
commit moves it to service_ldap_getDnTreesToDump() thus allowing other
parts to use that logic.
Improves the "list-storages-locations" action to list per Service URLs

First version of that action only listed Storages' base path (the one
common to every Service).
With theses changes: each absolute, Service-dedicated target URLs are
listed. They can now truly be passed to duplicity when using "verify"
or "list-current-files".

Increments version to 0.1.7.