Merge branch 'next'

* next: (24 commits)
  hygiene, avoid shadow decl in divrem() routine, div(3) is stdlib
  chore, add build status indicator to README.md
  doc, mention new reference date in format.texi as well
  doc, leave a note about the Gregorian Reformation assumption in dateutils
  doc, explain new reference year for daisy dates
  chore, lift inlining pressure from __offs() offset finder in tzraw
  chore, lift inlining pressure from divrem() helper
  hygiene, rewrite tuidiv()/tuimod() calls in dt_tadd() in terms of divrem() inline
  chore, hygiene, eliminate __to_unix_epoch() copy in ltrcc, use public dt_to_unix_epoch() instead
  minor, avoid c99 (reverse) inlines and provide a public dt_to_unix_epoch() and dt_to_gps_epoch()
  minor, allow no left hand side in tzconv.m mex
  major, extend date range to 1601-01-01
  cosmetics, add whitespace between code and decls
  fix, lilian and julian offsets for 1753-based dates are off-by-one
  fix, PEBKAC, for 1753-based daisy dates compute the number of missing (leap) days properly
  fix, PEBKAC, for daisy-based epoch conversions define the offset in terms of daisy's base year
  hygiene, refer to dt-core's __to_unix_epoch() in dt-core-tz-glue
  fix, PEBKAC, for __jan00_daisy() and 1601 base use original YEAR arg for fix-ups
  fix, PEBKAC, 1601 lilian and julian dates are off by one
  minor, bring back zdiff handling (and %Z)
  ...
bump, release v0.2.4 is imminent

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, always update repositories

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, mention fmt-special.gperf source in EXTRA ltrcc SOURCES

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, make clear how to make dexpr-parser.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, avoid parallel builds of info stuff

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, actually write doc generated files into proper subdirs

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Revert "fix, avoid parallel builds of info stuff"

This reverts commit 4f9858ecfaf1d9136dd8a095b5861fd39736fb01.
fix, skip special format specifiers if build is for ltrcc

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'bld/dist' into next

* bld/dist:
  fix, skip special format specifiers if build is for ltrcc
  Revert "fix, avoid parallel builds of info stuff"
  fix, PEBKAC, actually write doc generated files into proper subdirs
  fix, avoid parallel builds of info stuff
  fix, PEBKAC, make clear how to make dexpr-parser.h
  fix, mention fmt-special.gperf source in EXTRA ltrcc SOURCES
Merge branch 'bld/travis' into next

* bld/travis:
  chore, always update repositories
Merge branch 'next'

* next:
  fix, skip special format specifiers if build is for ltrcc
  Revert "fix, avoid parallel builds of info stuff"
  fix, PEBKAC, actually write doc generated files into proper subdirs
  fix, avoid parallel builds of info stuff
  fix, PEBKAC, make clear how to make dexpr-parser.h
  fix, mention fmt-special.gperf source in EXTRA ltrcc SOURCES
  chore, always update repositories