more specific annotation of json

[WardCunningham]

We annotate json as we serve it so that the
client can adjust rendering. Example: green
border for pages served from plugins.

This commit moves the logic for applying the
plugin annotation to a point where we know
for sure that we are looking for plugin pages.

This fixes one issue mentioned in fedwiki/wiki-plugin-calculator#2

This pull is pending testing. @nrn has promised to help me straighten out my server build when he returns from jsconf tonight.

[WardCunningham]

This commit has been tested and been shown to work as expected. Merge at will.

My problem testing has been resolved by @nrn. Thanks.

I used npm link to connect the wiki-node and wiki-node-server repos. This causes the packageDir to point to the enclosing directory by default. If this directory also had all the plugins checked out then that would work ok. I didn't. The short term solution is to specify the packageDir on the command line.

 node bin/server.js -p 3090 --packageDir node_modules

This was enough to show that the revised server works correctly annotating normal plugins. I also tested the case where -d referred to a plugin repo (which I had checked out in ./test)

 node bin/server.js -p 3090 --packageDir node_modules -d ../test/wiki-plugin-calculator/

I've asked @nrn to explain how npm link interferes with the packageDir parameter and perhaps suggest a modification. If I misunderstand its purpose please let me know.

[nrn]

Found it easier to submit a pr for what I was thinking than try to explain it, think it's a little cleaner this way and the issue is fixed.