Revert "libpcp_pmda: change e_ext_t to expose pmdaInterface"

This reverts commit f856e2c17103540b87952e396f3a7de9cec9a66a.

Test failure is being observed in qa/628, this commit is the
current prime suspect (not sure why though, as yet):

$ ./check -q -l 628
628 27s ... - output mismatch (see 628.out.bad)
4c4
<     value 3
---
> No value(s) available!
16c16
<     value 4
---
> No value(s) available!

So, reverting temporarily and will reinstate after pcp-3.10.2
which is pending.
pmda papi: log errors that occur with no client context
docs: update changelog for pending release
qa fixes for situations where tests shouldn't be run

qa/661 - add _notrun test for simplejson.tool
qa/757 - add _notrun test for when no perfevents are found
qa/813 - add _notrun test for when no pmu metrics are found
qa/867 - add _notrun test for when no pmu metrics are found
Tweak spin-rawhide

Attempt to make spin-rawhide even more robust by making pcp-webjs
no longer dependent on a specific SourceX: keyword.  Also, change
repository urls to pcp.io based.
More qa tweaks based on availablity of papi metrics on current hardware

qa/903 - test for PAPI availability
qa/914 - test for PAPI availability
Merge branch 'lberk/dev' of ../lberk-dev into lberk-merge
pmda proc: add defensive coding measures for recent kernels

Current rawhide kernels are reportedly (fche, lukas) exposing a
problem where the /proc pid readdir gets pids that cannot later
be opened.  Have verified no earlier, released kernel has shown
this kind of behaviour (none of those in my QA farm, anyway) -
so it may yet change back.  But we're definitely able to defend
against it to improve pmdaproc resilience, which this commit is
an initial attempt toward.
build: update packaging for pending release
packaging: rpm spec tweaks to get epel5 going again
Revert "Revert "libpcp_pmda: change e_ext_t to expose pmdaInterface""

This reverts commit 6b26d4315270aaa7e572927af23fc2e83e0495b9.
build: update packaging and project forward for next release date
packaging: fix spec file problems found by rpmlint

Fixes the following rpmlint warnings:

- W: mixed-use-of-spaces-and-tabs
The specfile mixes use of spaces and tabs for indentation, which is a
cosmetic annoyance.  Use either spaces or tabs for indentation, not
both.

- pcp.src: W: invalid-url Source1: pcp-webjs.src.tar.gz
The value should be a valid, public HTTP, HTTPS, or FTP URL.
packaging: fix compat tmpdir renaming holes in debian postinst
packaging: add note re debian bugs fixed this release
pmdalinux: improve help text for network metrics

The following three metrics have a wrong description:
network.interface.in.frame network recv read frames ...
network.interface.in.fifo network recv read fifos ...
network.interface.out.fifo network send fifos ...

All three are actually error counters (see net/core/net-procfs.c:
dev_seq_printf_stats()).

Improve the description of all metrics taken from /proc/net/dev
and refer to the actual structure in the kernel for easier
referencing.
pmdalinux: resolve another case of valgrind/957 vs ioctl

Lukas reports the ifreq structure needs the same treatment as
the ethtool_cmd structure for the rawhide valgrind version.
Flip the order for the all access check in linux_proc
pmwebd build fixes for RHEL5

Needed some casting/declaration tweaks for compatibility with both
older and newer gcc/g++ (checked on 4.1.2 and 4.8.3), and with older
glibc.  Also, need to propagate cairo cflags from pkg-config, because
some intra-cairo include's require -I/usr/include/cairo.  Full
pmwebd/graphite/etc. goodness seen on RHEL5 32-bit VM.
perl pmdas: fix inst-handling edge case and pmda_inst_name

Fix an edge case in the array-based indom handling, when the
instance set becomes zero.  Also implemented hash-variant of
pmda_inst_name - previously this worked for arrays only.

Test qa/758 exercises both of these scenarious using a newly
added test_perl PMDA, based on the original test case from
Tall Paul Smith and Andy Trigg (thanks guys!).