Fix confusing names

[peterbourgon]

Closes #526.

@ChrisHines @basvanbeek — interested in a review?

@willfaught @terinjokes — likewise, and FYI.

[peterbourgon]

For the record,

#!/usr/bin/env fish

for pair in \
    "FromHTTPContext ContextToHTTP" \
    "ToHTTPContext   HTTPToContext" \
    "FromGRPCContext ContextToGRPC" \
    "ToGRPCContext   GRPCToContext" \
    "FromHTTPRequest HTTPToContext" \
    "ToHTTPRequest   ContextToHTTP" \
    "FromGRPCRequest GRPCToContext" \
    "ToGRPCRequest   ContextToGRPC"
  set fr (echo $pair | awk '{print $1}')
  set to (echo $pair | awk '{print $2}')
  echo change from $fr to $to
  find . -type f -name '*.go' -exec sed -i '' s/$fr/$to/ \{\} + # macOS syntax
end

[ChrisHines]

The code looks good. I think the docs have some broken grammar.

[ChrisHines]

I feel obligated to point out that JWT is an acronym for JSON Web Token, which makes the phrase "JWT token" repetitive. I believe a more grammatically correct phrasing is "... moves a JWT from request header to context."

[peterbourgon]

Fixed. Thank you.

[willfaught]

The "a" article use is now inconsistent (present with "JWT", absent with "request header" and "context"), not sure if that's intentional, not a big deal.

[willfaught]

"Context" seems to be in all of these names, so is it redundant? Would To/FromHTTP and To/FromGRPC be equally clear? I haven't taken a close look at the whole file, and I've never used the package, so I'm genuinely asking. :) If not, the names look good!