Attempt to replace run-unittest.sh by run-unittest.d. Inception

Testsuite: Fix calls to die to always include line numbers ...

'die' actually taking two parameters seems to be a little-known fact.

testsuite: Replace GNU-specific -f option with a custom implementation ...

This will allow Mac OSX users to run that part of the testsuite

Ability to run a single test + output overview log ...

if a an argument is provided to run-unittest.sh it is used as
a regex pattern to match the tests to run.

Merge remote-tracking branch 'upstream/stable' into merge_stable

prevent globbing and splitting of log arguments ...

- "$@" expands as expected in a string (like args.join(' '))

Add support for DragonFlyBSD ...

- Switch from /bin/sh to /usr/bin/env bash
- Ignore temporary and test-build files (gitignore)
- Untrack changes to source/dub/version_.d
- Handling 'isDragonflybsd'
- Use 'tr -d' instead of 'tr --deleted' which works on Linux and BSD based platforms
- Fix FRONTEND = unbound variable (test/run-unittest.sh)

Merge remote-tracking branch 'upstream/master' into merge_master ...

# Conflicts:
#	test/run-unittest.sh

fix failures (due to bash error flags)

unify flags and error handling ...

- also add trap ERR handler to report exact error location

test dynamic libs with inherited pic

Log [ERROR] on the line of a failure

spelling fixes

Echo test commands.

allow to specify ddox tool ...

- can be used to customize the ddox tool (and it's output)
- assumes similar commands/behavior

use DC instead of COMPILER ...

- so it's clear that it can be dmd/ldc2/gdc

don't abort test on first failure ...

- makes it easier to find all errors at once

Add --import-paths and --string-import-paths as options for 'dub describe' instead of a new command. Add some scripts for testing the output of each, and a smoke test for 'dub describe'.

directly run the dub init test scripts

add --version option to dub

Added unittest for basic usage cases.