use proper placeholder instead of input value

to prevent various search glitches

Author: martenson

client/galaxy/scripts/templates/tool_search.handlebars

@@ -1,3 +1,3 @@
-<input type="text" name="query" value="{{search_hint_string}}" id="tool-search-query" autocomplete="off" class="search-query parent-width" />
+<input type="text" name="query" placeholder="{{search_hint_string}}" id="tool-search-query" autocomplete="off" class="search-query parent-width" />
 <a id="search-clear-btn" title="clear search (esc)"> </a>
-<img src="{{spinner_url}}" id="search-spinner" class="search-spinner"/>
+<img src="{{spinner_url}}" id="search-spinner" class="search-spinner"/>

static/scripts/templates/tool_search.handlebars

@@ -1,3 +1,3 @@
-<input type="text" name="query" value="{{search_hint_string}}" id="tool-search-query" autocomplete="off" class="search-query parent-width" />
+<input type="text" name="query" placeholder="{{search_hint_string}}" id="tool-search-query" autocomplete="off" class="search-query parent-width" />
 <a id="search-clear-btn" title="clear search (esc)"> </a>
-<img src="{{spinner_url}}" id="search-spinner" class="search-spinner"/>
+<img src="{{spinner_url}}" id="search-spinner" class="search-spinner"/>