Previously, configuration would come from application:get_env/3 or
proplists:get_value/3. Now we standardize on a single format
for retrieving values from the environment or from a proplist.

Port improper iolist support from io_lib_format.erl & add tests

Reviewed-by: macintux

Signed-off-by: Brian L. Troutwine <brian.troutwine@adroll.com>

Signed-off-by: Brian L. Troutwine <brian.troutwine@adroll.com>

This is, perhaps, not the most ideal setup. It still ignores other
sinks but does bring logging back online after the appropriate delay.

Signed-off-by: Brian L. Troutwine <brian.troutwine@adroll.com>

This test only passes when run in isolation. That is, if you run the
suite solo everything is beautiful and nothing hurts. When run in the
group, it fails. By inspection it seems that no trace messages are
being sent and this causes the failure, for want of specific traces.

Signed-off-by: Brian L. Troutwine <brian.troutwine@adroll.com>

At this point in the work, the killer will correctly stop the
DEFAULT_SINK in the event of overload but our friend never comes back
up and lager stops working past this point.

Oops!

Error message:

=SUPERVISOR REPORT==== 10-Mar-2016::16:18:11 ===
     Supervisor: {local,lager_handler_watcher_sup}
     Context:    child_terminated
     Reason:     killed
     Offender:   [{pid,<0.63.0>},
                  {id,lager_handler_watcher},
                  {mfargs,{lager_handler_watcher,start_link,undefined}},
                  {restart_type,temporary},
                  {shutdown,5000},
                  {child_type,worker}]

=SUPERVISOR REPORT==== 10-Mar-2016::16:18:11 ===
     Supervisor: {local,lager_handler_watcher_sup}
     Context:    child_terminated
     Reason:     killed
     Offender:   [{pid,<0.59.0>},
                  {id,lager_handler_watcher},
                  {mfargs,{lager_handler_watcher,start_link,undefined}},
                  {restart_type,temporary},
                  {shutdown,5000},
                  {child_type,worker}]

=PROGRESS REPORT==== 10-Mar-2016::16:18:11 ===
          supervisor: {local,lager_sup}
             started: [{pid,<0.113.0>},
                       {id,lager},
                       {mfargs,{gen_event,start_link,[{local,lager_event}]}},
                       {restart_type,permanent},
                       {shutdown,5000},
                       {child_type,worker}]

Signed-off-by: Brian L. Troutwine <brian@troutwine.us>

Signed-off-by: Brian L. Troutwine <brian@troutwine.us>

Otherwise `lager_transform` fails after de9012628a

The error message is:

    test/pr_nested_record_test.erl: error in parse transform 'lager_transform': {function_clause,
                                                 [{lager_transform,
                                                   '-walk_ast/2-fun-0-',
                                                   [{typed_record_field,
                                                     {record_field,5,
                                                      {atom,5,field1}},
                                                     {type,5,term,[]}}],
                                                   [{file,
                                                     "src/lager_transform.erl"},
                                                    {line,62}]},

API to explicitly call log rotation

Reviewed-by: macintux

Do not add logroot in expand_path sometimes

Reviewed-by: bsparrow435

Option to not reformat error_logger messages

Reviewed-by: macintux

If expand_path/1 already contains LogRoot in its RelPath, do not
add it again.

Close file right after rotation

Reviewed-by: bsparrow435

Start traces after extra sinks are started

Reviewed-by: macintux

Bump goldrush to 0.1.8 for not equal filters

Reviewed-by: macintux

Fix internal tuple argument order

Reviewed-by: macintux

Before, the old file was still being used until the next
`check_interval`, where the file was recreated and reopened.

Support for separate sink for error_logger messages

Previously, if you configured a trace to use an
extra sink, you'd get a noproc error. Addresses
issue #296 on github.

Forward port #292 to 3.x branch

Reviewed-by: shino

255 is a valid ISO-8859-1 character. This was fixed
on 2.x by #292. Forward port the fix into 3.x.

Function for printing stacktrace in human readable form

* Add formatting options to align text differently if desired
* Fix some typos in comments and docs
* Optionally print all metadata
* Fix R15 compatibility