Switch several category routes over to diesel

[jtgeibel]

All tests are green on stable and beta, however I think I'm hitting a bug in nightly as I get a segfault on the test krate::index_queries with nightly rustc 1.20.0-nightly (445077963 2017-06-20).

$ RUST_TEST_THREADS=1 RUST_BACKTRACE=1 rustup run beta cargo test krate::index_queries --verbose
[...]
running 1 test
test krate::index_queries ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 98 filtered out

$ RUST_TEST_THREADS=1 RUST_BACKTRACE=1 rustup run nightly cargo test krate::index_queries --verbose
[...]
running 1 test
test krate::index_queries ... error: process didn't exit successfully: `/home/jtgeibel/repos/github.com/rust-lang/crates.io/target/debug/deps/all-12d198baf6ed1586 krate::index_queries` (signal: 4, SIGILL: illegal instruction)

[jtgeibel]

Sometimes when running the test on nightly, I get this random failure for this test. The issue seems intermittent and non-deterministic.

I do not get the NOTICE: text-search query doesn't contain lexemes: "" output on beta when running this test.

When the test crashes, it sometimes crashes with an illegal instruction and other times with a segfault.

running 1 test
test krate::index_queries ... NOTICE:  text-search query doesn't contain lexemes: ""
NOTICE:  text-search query doesn't contain lexemes: ""
NOTICE:  text-search query doesn't contain lexemes: ""
FAILED

failures:

---- krate::index_queries stdout ----
        thread 'krate::index_queries' panicked at 'assertion failed: `(left == right)` (left: `0`, right: `1`)', src/tests/krate.rs:171
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at /checkout/src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at /checkout/src/libstd/sys_common/backtrace.rs:60
             at /checkout/src/libstd/panicking.rs:355
   3: std::panicking::default_hook
             at /checkout/src/libstd/panicking.rs:365
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:549
   5: std::panicking::begin_panic
             at /checkout/src/libstd/panicking.rs:511
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:495
   7: all::krate::index_queries
             at src/tests/krate.rs:171
   8: <F as test::FnBox<T>>::call_box
             at /checkout/src/libtest/lib.rs:1451
             at /checkout/src/libcore/ops/function.rs:143
             at /checkout/src/libtest/lib.rs:140
   9: __rust_maybe_catch_panic
             at /checkout/src/libpanic_unwind/lib.rs:98


failures:
    krate::index_queries

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 98 filtered out

[Mark-Simulacrum]

I'm attempting to bisect the segfault here.

[carols10cents]

I decided I liked a bit of both PRs so I merged them both in :)