archive/tar: support posix mode

[bradfitz]

for >100 byte filenames, we should support the posix ("pax") tar mode,

http://pubs.opengroup.org/onlinepubs/009695399/utilities/pax.html

(see "EXTENDED DESCRIPTION")

[rsc]

Comment 1:

Status changed to Accepted.

[rsc]

Comment 2:

Labels changed: added go1.1.

[rsc]

Comment 3:

Labels changed: added size-m.

[rsc]

Comment 4:

Labels changed: added suggested.

[minux]

Comment 5:

Issue #4549 has been merged into this issue.

[dsymonds]

Comment 6:

It's been getting worked on in https://golang.org/cl/6700047/ by shanemhansen.

Labels changed: added priority-soon, packagechange, removed priority-later, suggested.

Status changed to Started.

[rsc]

Comment 7:

Labels changed: added priority-later, removed priority-soon.

[dsymonds]

Comment 8:

This issue was closed by revision 1068279.

Status changed to Fixed.