v1.2.0

This new release introduces:
  * A new method SetReportCaller in the Logger to enable the file, line and calling function from which the trace has been issued
  * A new trace level named Trace whose level is below Debug
  * A configurable exit function to be called upon a Fatal trace
  * The Level object now implements encoding.TextUnmarshaler interface

Update changelog for v1.1.1 release

Update changelog for v1.1.0 release

Merge branch 'moriyoshi/refix-707' of git://github.com/moriyoshi/logr…

…us into fix_firehooks

changelog: add 1.0.5

changelog: 1.0.4

changelog: bump to v1.0.3

add changelog entry about making SetLevel public

readme: link to comment on casing

changelog: bump to v1.0.0