hgweb: align entries in "changelog" and "revisions" pages of "spartan" style Before this patch, each log entries in "changelog" and "revisions" pages of "spartan" style are not aligned by column, because: - each log entries are separated "<table>" entries, and - there are no fixed "width" information for each "<th>"/"<td>" entries This patch aligns entries in "changelog" and "revisions" pages of "spartan" style by: - adding 'label' class to '<th>' for 'age' information, and - setting 'width' of '<th class="label">' with fixed size 'class="age"' is not used for this purpose, because it is also used to set "bold" font-weight "16em" seems to be wide enough to show date information fully, when web browser disables (or doesn't support) javascript.