Better warnings (and less breakage) when running subprocesses

[itamarst]

Fixes #117.

Memory tracking in subprocesses/multiprocessing is still not supported!

[github-actions]

Benchmark results

diff --git a/benchmarks/results/lots-of-peaks.json b/benchmarks/results/lots-of-peaks.json
index 70e5002..a54e4dd 100644
--- a/benchmarks/results/lots-of-peaks.json
+++ b/benchmarks/results/lots-of-peaks.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-4581665,-]{+4585490,+}
    "D1mw": [-2834520,-]{+2853777,+}
    "DLmr": [-1550571,-]{+1514950,+}
    "DLmw": [-1791810,-]{+1797325,+}
    "Dr": [-245534019,-]{+242423784,+}
    "Dw": [-95377424,-]{+93327927,+}
    "I1mr": [-4277300,-]{+4323368,+}
    "ILmr": [-15866,-]{+16524,+}
    "Ir": [-932200278,-]{+919043299,+}
    "Overall": [-1420633071-]{+1401709520+}
}
diff --git a/benchmarks/results/multithreading-1.json b/benchmarks/results/multithreading-1.json
index db44d64..f119057 100644
--- a/benchmarks/results/multithreading-1.json
+++ b/benchmarks/results/multithreading-1.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-2808825,-]{+2766644,+}
    "D1mw": [-544188,-]{+537811,+}
    "DLmr": [-122662,-]{+120946,+}
    "DLmw": [-120659,-]{+123908,+}
    "Dr": [-103979511,-]{+98965289,+}
    "Dw": [-43469910,-]{+40534549,+}
    "I1mr": [-2395315,-]{+2429852,+}
    "ILmr": [-9899,-]{+10548,+}
    "Ir": [-357299406,-]{+338610875,+}
    "Overall": [-535338739-]{+508710001+}
}
diff --git a/benchmarks/results/pystone.json b/benchmarks/results/pystone.json
index eae0fa4..a10bd83 100644
--- a/benchmarks/results/pystone.json
+++ b/benchmarks/results/pystone.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-5614673,-]{+6912759,+}
    "D1mw": [-1628287,-]{+1609913,+}
    "DLmr": [-92348,-]{+88988,+}
    "DLmw": [-98625,-]{+100562,+}
    "Dr": [-381027076,-]{+375828259,+}
    "Dw": [-155994843,-]{+152958826,+}
    "I1mr": [-9519850,-]{+9740754,+}
    "ILmr": [-9729,-]{+10363,+}
    "Ir": [-1228557263,-]{+1211826239,+}
    "Overall": [-1838651482-]{+1819664418+}
}
diff --git a/benchmarks/results/version.txt b/benchmarks/results/version.txt
index 133d14b..5f61fa6 100644
--- a/benchmarks/results/version.txt
+++ b/benchmarks/results/version.txt
@@ -1 +1 @@
[-0.14.2.dev23+gade2380.d20210207-]{+0.14.2.dev30+ga6c2dd8.d20210211+}

[github-actions]

Benchmark results

diff --git a/benchmarks/results/lots-of-peaks.json b/benchmarks/results/lots-of-peaks.json
index 70e5002..0d565ad 100644
--- a/benchmarks/results/lots-of-peaks.json
+++ b/benchmarks/results/lots-of-peaks.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-4581665,-]{+4586081,+}
    "D1mw": [-2834520,-]{+2853409,+}
    "DLmr": [-1550571,-]{+1505464,+}
    "DLmw": [-1791810,-]{+1796805,+}
    "Dr": [-245534019,-]{+242428490,+}
    "Dw": [-95377424,-]{+93328303,+}
    "I1mr": [-4277300,-]{+4316384,+}
    "ILmr": [-15866,-]{+16463,+}
    "Ir": [-932200278,-]{+919103353,+}
    "Overall": [-1420633071-]{+1401445602+}
}
diff --git a/benchmarks/results/multithreading-1.json b/benchmarks/results/multithreading-1.json
index db44d64..b297f6b 100644
--- a/benchmarks/results/multithreading-1.json
+++ b/benchmarks/results/multithreading-1.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-2808825,-]{+2765542,+}
    "D1mw": [-544188,-]{+537147,+}
    "DLmr": [-122662,-]{+120883,+}
    "DLmw": [-120659,-]{+123905,+}
    "Dr": [-103979511,-]{+98968815,+}
    "Dw": [-43469910,-]{+40536826,+}
    "I1mr": [-2395315,-]{+2430320,+}
    "ILmr": [-9899,-]{+10541,+}
    "Ir": [-357299406,-]{+338620373,+}
    "Overall": [-535338739-]{+508717920+}
}
diff --git a/benchmarks/results/pystone.json b/benchmarks/results/pystone.json
index eae0fa4..71e886d 100644
--- a/benchmarks/results/pystone.json
+++ b/benchmarks/results/pystone.json
@@ -1,12 +1,12 @@
{
    "D1mr": [-5614673,-]{+6912946,+}
    "D1mw": [-1628287,-]{+1610030,+}
    "DLmr": [-92348,-]{+89009,+}
    "DLmw": [-98625,-]{+100555,+}
    "Dr": [-381027076,-]{+375828487,+}
    "Dw": [-155994843,-]{+152959034,+}
    "I1mr": [-9519850,-]{+9740707,+}
    "ILmr": [-9729,-]{+10366,+}
    "Ir": [-1228557263,-]{+1211821622,+}
    "Overall": [-1838651482-]{+1819661775+}
}
diff --git a/benchmarks/results/version.txt b/benchmarks/results/version.txt
index 133d14b..5e546ad 100644
--- a/benchmarks/results/version.txt
+++ b/benchmarks/results/version.txt
@@ -1 +1 @@
[-0.14.2.dev23+gade2380.d20210207-]{+0.14.2.dev31+g1b74e3d.d20210211+}