Add some tests for the Jaunch configurator itself

test/jaunch.t

@@ -0,0 +1,41 @@
+Setup:
+
+  $ cd "$TESTDIR/../app"
+
+Now test stuff.
+
+  $ ./jaunch/jaunch-linux-x64
+  Hello! You have found the Jaunch configurator.
+  Your curiosity is an asset. :-)
+
+  This program is intended to be called internally by Jaunch's native
+  launcher executable. Normally, you do not need to run it yourself.
+
+  However, if you wish, you can test its behavior by passing command line
+  arguments in the same manner as you would to Jaunch's native launcher,
+  prepended by the name of the native launcher executable.
+
+  For example, if your native launcher is called fizzbuzz, you could try:
+
+      jaunch fizzbuzz --heap 2g --debugger 8000
+
+  and watch how Jaunch transforms the arguments.
+
+  You can learn similar information using Jaunch's --dry-run option:
+
+      fizzbuzz --heap 2g --debugger 8000 --dry-run
+
+  For more details, check out the jaunch.toml file. Happy Jaunching!
+  [1]
+
+  $ jaunch/jaunch-linux-x64 parsy a b c
+  LAUNCH
+  /*/libjvm.so (glob)
+  2
+  -Djava.class.path=/*/lib/parsington-3.1.0.jar* (glob)
+  -Xmx128m
+  org/scijava/parsington/Main
+  3
+  a
+  b
+  c