Improve nipap-cli handling of default_vrf

The configuration option 'default_vrf' has now been replaced with two
new ones;
 - 'default_vrf_rt' only affects address adds/edits/removals and in
   which VRF to search when adding a member prefix to a pool for the
   first time - if the pool already has member prefixes, the implied VRF
   of the pool will be used.
 - 'default_list_vrf_rt' control the default VRF for listing/search
   operations, ie 'nipap address list'.

The output of VRF related information has been changed for all commands
to include both the VRF RT as well as the name. All search strings and
similar are now enclosed in single quotes when used in various messages
to make it clear what is a pool name and what is just part of the
message.

Some logic around handling the global VRF has been removed since there
is always a VRF (change made quite long ago actually).

Part of #451.
Fixes #386.
Merge branch '451-default_vrf'
Fix listing of stuff in CLI

Fix logic to avoid print "No matching ... found" when number of result
fall on limit. Ie, 50 prefixes would pring "No matching prefixes found"
as the limit is set to 50.

Fixes #461.
Add column headers to address list

This adds column headers as well as a message showing which VRF we are
searching in.

Fixes #463.
Merge branch '461-listing-fix'
Update NEWS file for coming v0.24 release
Fix for Travis-CI
Added ojnipap API function to remove prefixes

The Oracle API now supports removing prefixes. Also renamed a function
parameter to clearify its function.
Various fixes to Java code

* Added serialVersionUID to classes which implements Serializable
* Removed unnecessary 'this's
Small fix for doc miss

I must have changed this by mistake. Changing it back!
Thanks to dosomder for pointing it out :)
Removed debug statements
Merge branch 'ojnipap_cleanup_and_remove'
Added parent & neighbors to ext. key search

Modified the ojnipap API function searchPrefixExtKey to include
neighboring and closest parent prefixes.
Revert renaming of radio buttons for prefix type

Silly change which broke updates by the logic for which prefix types are
allowed. Reverting back to previous names.

Fixes #459.
Merge branch '459-prefix-type-host-disabled'
Avoid creating too many instances of auth classes

Every time the AuthFactory is instanciated it creates instances of every
auth backend registered in the config file, which really doesn't make
sense to me. In combination with SQLite never closing its file
descriptors, this leads to exhaustion of fds.

Altered the AuthFactory constructor to not create these instances.
Add functions to create & upgrade sqlite database

The SqliteAuth class  has new functions to check that the database
schema is of the latest "version" and to upgrade the database.

nipapd is now performing pre-start checks to make sure that the sqlite
database is of the latest version, which is required for correct
operation. If not, it will exit and print an error message.

nipap-passwd has new arguments to check if the db is of latest version,
to create a new database and upgrade an existing database.

Part of #438.
Fix --version argument to nipapd

Was missing an import statement.

Fixes #470.
Merge branch '438-readonly-sqlite'
Fix copyright year and reorder argument order