- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

When an asm location cannot be resolved to a function the cost
will be spread as small value and then filtered by the threshold.
As a first step solution display the number of event that cannot
be resolved as a valid function location.

MFC after: 1week

Move fatal error at the right place.
Fix exit from top mode when checking if PMC is available.

MFC after: 3 days

Improve "top" header by:
- Display sample received per PMCs (or merged PMCs).
- Display percentage vs all samples

Bug fixed:
- no display on serial terminal in top mode.
- display alignment for continuation string.
- correct invalid value used for display limit.

MFC after: 3 days

- Reorganize code in 'plugin' to share log processing.
- Kcachegrind (calltree) support with assembly/source
code mapping and call count estimator (-F).
- Top mode for calltree and callgraph plugin (-T).

MFC after: 1 month