Consolidate button styles

This patchset will create consistent button styling according
to the styleguide and remove redundant button styles by creating
reusable button classes.

This patchset also implements a consistent strategy for including
icon assets. Currently, svg icons are imported as CSS background
images or inlined into the markup. Inlining an svg is preferred,
especially when used with buttons or links so the colors can
be easily changed for different states (hover, focus, disabled)
without having to request variants.
The icon provider allows us to inline svgs without cluttering
the markup. Webpack config was adjusted to use svg-inline-loader
when resolving svgs that are used by the icon provider directive.

- All svgs were optimized to remove unncessary information.
- Removed unused svg color variants
- Moved icons used by icon provider to separate directory to
  avoid Webpack parsing the files twice
- Small changes to navigation icons

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I1ca214b74fc502e6b6e760cfee88b48110237c43
diff --git a/app/overview/controllers/system-overview-controller.html b/app/overview/controllers/system-overview-controller.html
index 0403a85..34e5611 100644
--- a/app/overview/controllers/system-overview-controller.html
+++ b/app/overview/controllers/system-overview-controller.html
@@ -2,7 +2,7 @@
 <div class="overview">
   <div class="row column">
     <h1 class="inline">{{dataService.hostname}}</h1>
-    <button class="link" ng-click="edit_hostname = !edit_hostname">Edit</button>
+    <button class="btn  btn-tertiary" ng-click="edit_hostname = !edit_hostname">Edit</button>
   </div>
   <section class="row">
     <div class="column large-8">
@@ -122,7 +122,7 @@
         </div>
         <a href="#/server-control/remote-console" class="no-icon quick-links__item">
           <p class="inline quick-links__label">Serial over LAN console</p>
-          <span class="btn-pop-out inline float-right"></span>
+          <icon file="icon-launch.svg" class="float-right"></icon>
         </a>
         <a href="#/configuration/network" class="quick-links__item">
           <p class="inline quick-links__label">Edit network settings</p>
@@ -169,7 +169,7 @@
               </div>
             </div>
             <div class="column small-2 large-1">
-              <button class="accord-trigger" aria-hidden="true"></button>
+              <span class="accord-trigger" aria-hidden="true"></span>
             </div>
           </div>
         </div>
@@ -191,17 +191,11 @@
     <!-- accessibility only; used for screen readers -->
     <div class="screen-reader-offscreen modal-description">Edit hostname</div>
     <div class="page-header ">
-      <h2 class="modal-title"><span class="icon icon__info"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
-            <path d="M18 14h-6v2h1v6h-2v2h8v-2h-2z" />
-            <circle cx="16" cy="10" r="2" />
-            <path
-              d="M16 2C8.269 2 2 8.269 2 16s6.269 14 14 14 14-6.269 14-14S23.731 2 16 2zm0 26C9.383 28 4 22.617 4 16S9.383 4 16 4s12 5.383 12 12-5.383 12-12 12z" />
-          </svg></span>
-        Edit hostname
+      <h2 class="modal-title">
+        <icon class="icon__info" file="icon-information.svg"></icon>Edit hostname
       </h2>
     </div>
     <div class="modal__content">
-
       <form name="edit_hostname_text">
         <label for="editServerName">Hostname</label>
         <p class="label__helper-text">Hostname must be less than 64 characters and must not contain spaces.</p>
@@ -214,9 +208,9 @@
       </form>
     </div>
     <div class="modal__button-wrapper">
-      <button class="inline btn-secondary"
+      <button class="btn  btn-secondary"
         ng-click="edit_hostname= false; newHostname = dataService.hostname">Cancel</button>
-      <button class="inline btn-primary" ng-click="saveHostname(newHostname);" ng-disabled="edit_hostname_text.$invalid"
+      <button class="btn  btn-primary" ng-click="saveHostname(newHostname);" ng-disabled="edit_hostname_text.$invalid"
         ng-class="{'disabled' : edit_hostname_text.$invalid}">Save</button>
     </div>
   </div>