Add AvalancheSchedulerSvc and clean up the ForwardSchedulerSvc

See merge request !288

Make sure that entries in m_flatUniqueAlgList are actually unique

See merge request !255

Conflicts:
	GaudiHive/src/AlgResourcePool.cpp

Fix HistoStats in GaudiUtils to prevent floating point exceptions due to 'bad' return values

See merge request !270

allow multiple handlers for a protocol in VFSSvc

See merge request !295

Support for AthSequencers in Scheduler

See merge request !287

Attribute unmet INPUT dependencies to a DataLoader Algorithm

See merge request !269

See merge request !79

Closes GAUDI-1276

See merge request !267

fixes to CMake modules

Closes LBCORE-1304

See merge request !298

Closes LBCORE-1228

See merge request !289

gdb can be found in /usr/bin, in which case its directory must
not be prepended to the custom PATH

Search for heptools version only in target platform installs

Closes GAUDI-1280

See merge request !276

See merge request !275

see LBCORE-1304

minor fixes to exception reports in IncidentSvc

See merge request !291

do not require Gaudi::Property::ValueType to be default constructible

See merge request !271

syncing MR-288 with upstream master (one conflict resolved in ForwardSchedulerSvc.cpp and added concurrency flags to AvalancheSchedulerSvc.cpp)

See merge request !292

GaudiAlg::ID optimisation

See merge request !283

use std::showpoint instead of std::fixed to print numbers

See merge request !254

filter stdout for tests to hide removal of ErrorCounter property

See merge request !284

to enable debug symbols in optimized builds

IProperty::getProperty("NAME") will throw an exception if NAME doesn't exist.

The static ConcurrencyFlags allows easy access to information
about the number of threads, concurrent events, and processes.

For running in serial, numThreads == 0, numConcEvents == 0,
numProcs == 0, useful to distinguish between running serial,
and running MT with 1 thread, or MP with 1 process.

See merge request !277

a BINARY_TAG like x86_64-ubuntu1604-gcc54-opt+o3 will use -O3 instead of the
default (currently -O2)