Currently parse_log.py skips all non timestamped lines
only once. When resuming a solver and appending to the
same log file, it creates more non timestamped log lines.
This change allows the script to silently skip those lines.

sig-ce learns to ignore by zeroing out the loss/diff at targets equal to
the configured `ignore_label`.

n.b. as of now the loss/diff are not properly normalized when there are
ignored targets. sig-ce loss should adopt the same normalization options
as softmax loss.

sig-ce loss handles all the same normalizations as the softmax loss;
refer to #3296 for more detail.

this preserves the default normalization for sig-ce loss: batch size.

Sigmoid Cross-Entropy Loss: ignore selected targets by `ignore_label`

Support solver resumes in parse_log.py

Avoids missing return values during build

the solver checks its proto type (SolverParameter.type) on
instantiation:

- if the proto type is unspecified it's set according to the class type
  `Solver::type()`
- if the proto type and class type conflict, the solver dies loudly

this helps avoid accidental instantiation of a different solver type
than intended when the solver def and class differ. guaranteed type
information in the SolverParameter will simplify multi-solver
coordination too.

OS X: build with latest SDK by default

Add missing spaces besides equal signs in batch_norm_layer.cpp

Solver: check and set type to reconcile class and proto type

…into matlab_interface