Interface proposal : pull request 4

[yoann-heitz]

This is the fourth pull request for the proposal for a plugin interface for the rocprof command. In this pull request, the <API>_trace_entry_t structures defined in the previous pull requests have been moved to a new header.

Installation files have been modified to take into account this new header.

Relative to the third pull request, this one starts at commit 769987e