portico: Remove form-horizontal class from some portico pages.

This commit removes form-horizontal class from password reset
pages (page in which user enters the email and the page where
user sets the new password) and user register page.

We can safely remove the form-horizontal class, since the
vertical-align property is already applied by other CSS
in bootstrap and margin is overridden by CSS in
portico_signin.css.

For checkbox type inputs, the display property is already set
to inline-block by browser for all input elements but it is
eventually computed to "block" since float property for this
element is set to left. So, setting display property is not
necessary for checkbox input.

For the help-inline elements, the display and margin properties
are overridden in portico_signin.css and vertical-align property
is handled by CSS for "help-inline" class in bootstrap.css.

templates/zerver/register.html

@@ -28,7 +28,7 @@ Form is validated both client-side using jquery-validation (see signup.js) and s
             {% endtrans %}
         </div>
 
-        <form method="post" class="form-horizontal white-box" id="registration" action="{{ url('accounts_register') }}">
+        <form method="post" class="white-box" id="registration" action="{{ url('accounts_register') }}">
             {{ csrf_input }}
 
             <fieldset class="org-registration">

templates/zerver/reset.html

@@ -16,7 +16,7 @@
 
             <p>Forgot your password? No problem, we'll send a link to reset your password to the email you signed up with.</p>
 
-            <form method="post" class="form-horizontal" action="{{ url('password_reset') }}">
+            <form method="post" action="{{ url('password_reset') }}">
                 {{ csrf_input }}
                 <div class="new-style">
                     <div class="input-box horizontal">

templates/zerver/reset_confirm.html

@@ -18,7 +18,7 @@
             <!-- TODO: Ask about meta viewport 1:1 scaling -->
 
             {% if validlink %}
-            <form method="post" id="password_reset" class="form-horizontal" autocomplete="off">
+            <form method="post" id="password_reset" autocomplete="off">
                 {{ csrf_input }}
                 <div class="input-box" id="email-section">
                     <label for="id_email">{{ _("Email") }}</label>