http/json: fix wrong return type of cJSON_type_to_string

We return c style strings instead of strings of C++ String class.

Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com>
http/json: be more informative about the json schema mismatch error

Before this patch, we might get error meessage like:
    info: HTTP request throw a schema_mismatch_exc_t with what = Expected object instead got: 2

However, we can tell user more by:
    info: HTTP request throw a schema_mismatch_exc_t with what = Expected 'object' instead got 'number': 2

Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com>
Merge pull request #2263 from Aleaxander/yliu-json-trivial-enhancement

yliu json trivial enhancement
Fix v8 dependency issues in the ubuntu package

Closes #2101
Closes #2261
OTS review by @Tryneus
Fix v8 dependency issues in the ubuntu package

Closes #2101
Closes #2261
OTS review by @Tryneus
Release notes for 1.12.3
Second draft
Merge pull request #2267 from rethinkdb/atnnn/notes

Release notes for 1.12.3
Added page_t::is_deferred_loading and used it in an assertion in current_page_t::should_be_evicted.
Merge branch 'sam_2260' into v1.12.x
Merge branch 'v1.12.x' into next
Merge branch 'next' into sam_2130

Conflicts:
	src/buffer_cache/alt/page_cache.cc