Change @since and @deprecated notes to 1.22

Using the following command line, I have found doc comments mentioning
"1.21" when they should mention "1.22" instead, which I have fixed
manually:

git diff REL1_21 | grep --color=always -C 10 -iE \
'^\+.*(since|deprecated).*1\.21(\D|$)' | aha > oldver.html

I also moved the release notes for I1987190f ("Combine JavaScript and
JSON encoding logic") from RELEASE-NOTES-1.21 to RELEASE-NOTES-1.22
because I had reverted the commit on REL1_21 only (see Id3b88102 and
bug 47431 for the rationale).

Change-Id: I11b917a371e07267dfa98b8449776d0c1cb29b15
Follows-Up: I25cf5a94f6e47f85a9d0b80cc1c9c9f957288478
Follows-Up: I3d72e4105f6244b0695116940e62a2ddef66eb66
Follows-Up: I3faa9c3e8107c6e46cdf21f8c18adda1f42890d7
Follows-Up: I6aab19c8d68bf47beddad42632b0360a7b12f251
Follows-Up: I86368821fc2cd0729df5342b8572eb470c0f77a0
Follows-Up: Id3b88102e768318e3605a19e9952121091a40915
Follows-Up: Ie667088010e24eb6cb569f9e8e8e2553005223eb