More fixes for relative urls when running Grafana under a different sub path (#10470)

* Add nginx proxy docker container

Ease test/verification of running Grafana thru a reverse proxy

* Add apache proxy docker container

Ease test/verification of running Grafana thru a reverse proxy

* Fix relative urls for reset password page

* Fix relative urls for signup page

* Fix relative urls for login page

* Fix relative urls edit plugin page

public/app/partials/login.html

@@ -63,7 +63,7 @@
         <div class="login-signup-title p-r-1">
           New to Grafana?
         </div>
-        <a href="/signup" class="btn btn-medium btn-signup btn-p-x-2">
+        <a href="signup" class="btn btn-medium btn-signup btn-p-x-2">
           Sign Up
         </a>
       </div>

public/app/partials/reset_password.html

@@ -12,7 +12,7 @@
 				<button type="submit" class="btn btn-success" ng-click="sendResetEmail();" ng-disabled="!sendResetForm.$valid">
 					Reset Password
 				</button>
-				<a href="/login" class="btn btn-inverse">
+				<a href="login" class="btn btn-inverse">
 					Back
 				</a>
 
@@ -22,7 +22,7 @@
 			An email with a reset link as been sent to the email address. <br>
 			You should receive it shortly.
 			<div class="p-t-1">
-				<a href="/login" class="btn btn-success p-t-1">
+				<a href="login" class="btn btn-success p-t-1">
 					Login
 				</a>
 			</div>

public/app/partials/signup_step2.html

@@ -40,7 +40,7 @@
         <button type="submit" class="btn btn-success" ng-click="ctrl.submit();" ng-disabled="!signUpForm.$valid">
           Sign Up
         </button>
-        <a href="/login" class="btn btn-inverse">
+        <a href="login" class="btn btn-inverse">
             Back
         </a>
       </div>