Improve formatting, add missing newlines

Summary:
Improve formatting

Task ID: #

Blame Rev:

Test Plan:
make

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D29829
Replace exception by setting valid_ = false in DBIter::MergeValuesNewToOld()

Summary: Replace exception by setting valid_ = false in DBIter::MergeValuesNewToOld().

Test Plan:
Not sure if I am right at this, but it seems we currently don't have a good
way to test that code path as it requires dynamically set merge_operator = nullptr
at the time while Merge() is calling.

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29811
Fix compile warning in db_stress.cc on Mac

Summary:
Fix the following compile warning in db_stress.cc on Mac
tools/db_stress.cc:1688:52: error: format specifies type 'unsigned long' but the argument has type '::google::uint64' (aka 'unsigned long long') [-Werror,-Wformat]
    fprintf(stdout, "DB-write-buffer-size: %lu\n", FLAGS_db_write_buffer_size);
                                           ~~~     ^~~~~~~~~~~~~~~~~~~~~~~~~~
                                           %llu

Test Plan:
make
Replace exception by assertion in autovector

Summary: Replace exception by assertion in autovector

Test Plan: autovector_test

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29847
Fix compile warning in db_stress

Summary:
Fix compile warning in db_stress

Test Plan:
make db_stress
Remove the use of exception in WriteBatch::Handler

Summary:
Remove the use of exception in WriteBatch::Handler.  Now the default
implementations of Put, Merge, and Delete in WriteBatch::Handler are no-op.

Test Plan:
Add three test cases in write_batch_test
./write_batch_test

Reviewers: sdong, igor

Reviewed By: sdong, igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29835
Replace runtime_error exception by abort() in thread_local

Summary: Replace runtime_error exception by abort() in thread_local

Test Plan: make dbg -j32

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29853
Remove the compability check on log2 OS_ANDROID as it's already blocked by ROCKSDB_LITE

Summary:
Remove the compability check on log2 OS_ANDROID as it's already blocked by ROCKSDB_LITE

Test Plan:
make OPT="-DROCKSDB_LITE -DOS_ANDROID" shared_lib -j32
make shared_lib -j32