Make HTML button strings shorter

The HTML buttons shown when viewing a bug currently have two words each.
On displays with limited horizontal width, buttons frequently split
across multiple lines which is very ugly.

Additionally, from a usability perspective, it is better to reduce the
number of words on the screen. By using only single words to describe
the action performed by each button, the interface is simplified and
less cluttered.

"Update Issue" has been changed to "Edit" as it is more specific.
"Update" could mean any number of things and doesn't particularly imply
that clicking the button lets you change/edit the bug fields.

lang/strings_english.txt

@@ -566,10 +566,10 @@ $s_bug_deleted_msg = 'Issue has been deleted...';
 
 # bug_delete_page.php
 $s_delete_bug_sure_msg = 'Are you sure you wish to delete this issue?';
-$s_delete_bug_button = 'Delete Issue';
+$s_delete_bug_button = 'Delete';
 
 # bug_monitor.php
-$s_monitor_bug_button = 'Monitor Issue';
+$s_monitor_bug_button = 'Monitor';
 $s_unmonitor_bug_button = 'End Monitoring';
 
 # bug_file_add.php
@@ -1261,11 +1261,11 @@ $s_view_simple_link = 'View Simple';
 $s_viewing_bug_advanced_details_title = 'Viewing Issue Advanced Details';
 $s_product_build = 'Product Build';
 $s_system_profile = 'System Description';
-$s_update_bug_button = 'Update Issue';
+$s_update_bug_button = 'Edit';
 $s_bug_assign_to_button = 'Assign To:';
 $s_bug_status_to_button = 'Change Status To:';
-$s_reopen_bug_button = 'Reopen Issue';
-$s_move_bug_button = 'Move Issue';
+$s_reopen_bug_button = 'Reopen';
+$s_move_bug_button = 'Move';
 $s_attached_files = 'Attached Files';
 $s_publish = 'Publish';
 $s_cached = 'Cached';
@@ -1388,7 +1388,7 @@ $s_delete_relationship_button = 'Delete';
 $s_delete_relationship_sure_msg = 'Are you sure you wish to delete this relationship?';
 $s_relationship_warning_blocking_bugs_not_resolved = 'Not all the children of this issue are yet resolved or closed.';
 $s_relationship_warning_blocking_bugs_not_resolved_2 = '<b>Attention:</b> Not all the children of this issue are yet resolved or closed.<br />Before <b>resolving/closing</b> a parent issue, all the issues related as child with this one should be resolved or closed.';
-$s_create_child_bug_button = 'Create Clone';
+$s_create_child_bug_button = 'Clone';
 $s_bug_cloned_to = 'Issue cloned';
 $s_bug_created_from = 'Issue generated from';