Hyperlinks together importc like pragmas.
Starts backends.txt with bits from nimrodc.txt.
Hyperlinks back JavaScript target.
Starts nimrod calling backend section.
Adds nimrod to backend examples.
Adds examples of backend calling nimrod.
Mentions memory management.
Adds tidbit about threads.
Add keepIf proc and keepIfIt template to sequtils
Rewords C derivate backend. Refs #1299.
Mentions nodejs in js intro. Refs #1299.
Add missing operators for uint and uint64: `+=`, `-=`, `*=`
Add inc and dec for uint and uint64
Rename keepIfIt to keepItIf
Add type constraints for uint and uint64 to the System module's procs instead
fixes constant array indexing bug
Merge pull request #1312 from def-/missing-unsigned-operators

Add missing operators for uint and uint64: `+=`, `-=`, `*=`
Merge pull request #1301 from def-/sequtils-filter-directly

Add keepIf proc and keepIfIt template to sequtils
Merge pull request #1299 from gradha/pr_documents_interfacing

Documents backend interfacing
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel