RFR: 8171978: docs should use CSS-friendly <span> instead of <font>

[Jonathan Gibbons]

Please review this simple change to a macro in make/Javadoc.gmk.
It replaces use of the <font> tag with an equivalent CSS-friendly <span> 
tag.

-- Jon

JBS: https://bugs.openjdk.java.net/browse/JDK-8171978

Patch:

diff -r 449e1a137897 make/Javadoc.gmk
--- a/make/Javadoc.gmk Thu Dec 22 18:48:00 2016 +0000
+++ b/make/Javadoc.gmk Fri Dec 23 13:20:43 2016 -0800
@@ -148,10 +148,10 @@
  # arg 2: copyright url (optional)
  # arg 3: free-form text snippet (optional)
  define GenerateBottom
- <font size="-1">$(if $(strip $3), $(strip $3))<br> $(if \
+ <span style="font-size:smaller">$(if $(strip $3), $(strip $3))<br> $(if \
        $(strip $2),<a href="$(strip $2)">Copyright</a>,Copyright) \
        © $(strip $1), $(COPYRIGHT_YEAR), $(FULL_COMPANY_NAME). \
- $(COMPANY_ADDRESS). All rights reserved.</font>
+ $(COMPANY_ADDRESS). All rights reserved.</span>
  endef

  # Speed up finding by filling cache