json.== handles nil now
Fixed `==` for PTables, added test.
Merge pull request #1363 from Araq/devel

Merge devel into master
Hyperlinks echo variants with noSideEffect pragma. Refs #1379.
Remove unnecessary import
typo fix
replaced var with let in system.nim

Nitpicking.
Merge pull request #1394 from PavelVozenilek/patch-2

typo fix
Merge pull request #1396 from PavelVozenilek/patch-5

replaced few var with let in system.nim
fixes #1395
fixes #1391
Merge pull request #1382 from sjakobi/patch-1

Remove unnecessary import
Merge pull request #1381 from gradha/pr_links_echo_variants

Hyperlinks echo variants with noSideEffect pragma. Refs #1379.
fixes subtle interaction between closures and 'yield'
'[]' for crit bit trees doesn't need the 'var' parameter
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel
Fix #1392
Merge pull request #1399 from flaviut/patch-1

Fix #1392
More robust implementation for finding the beginning of the stack.

This patch inserts an extra stack frame above the function that
calls the actual Nimrod code and ensures that a reference to this
frame is stored as the stack bottom.
Add automatic MAP_POPULATE flag for opening read_only (MAP_PRIVATE) and shared (MAP_SHARED) mmap files.