Reorganize unit-tests and test workflow

+ Moved unit tests out of tests/ and into their respective modules.
+ Rewrite makefile and added these tasks:
  + <MODULE>/<SUBMODULE> -- byte-compile a specific module
  + test:<MODULE>/<SUBMODULE> -- runs tests for a specific module
  + testi -- run tests in an interactive session of Emacs (WIP)
  + run -- opens an Emacs session with this config; useful when it is in
    a non-standard location.

modules/tools/password-store/test/autoload-pass.el

@@ -0,0 +1,35 @@
+;; -*- no-byte-compile: t; -*-
+;;; tools/password-store/test/autoload-pass.el
+
+(defmacro -with-passwords! (buffer-args &rest body)
+  (declare (indent defun))
+  `(cl-letf
+       (((symbol-function 'auth-pass-parse-entry)
+         (lambda (entry)
+           (when (equal entry "fake/source")
+             '((secret . "defuse-account-gad")
+               ("login" . "HL2532-GANDI")
+               ("alt-login" . "hlissner")
+               ("email" . "henrik@lissner.net")
+               ("url" . "https://www.gandi.net/login"))))))
+     ,@body))
+
+;;
+(def-test! get-field
+  (-with-passwords!
+    (should (equal (+pass-get-field "fake/source" "login")
+                   "HL2532-GANDI"))
+    (should (equal (+pass-get-field "fake/source" "email")
+                   "henrik@lissner.net"))
+    (should (equal (+pass-get-field "fake/source" '("alt-login" "email"))
+                   "hlissner"))
+    (should (equal (+pass-get-field "fake/source" '("username" "email"))
+                   "henrik@lissner.net"))
+    (should-not (+pass-get-field "fake/source" '("x" "y" "z")))
+
+    (should-error (+pass-get-field "nonexistent/source" "login"))))
+
+(def-test! get-login
+  (-with-passwords!
+    (should (equal (+pass-get-user   "fake/source") "HL2532-GANDI"))
+    (should (equal (+pass-get-secret "fake/source") "defuse-account-gad"))))