faster SRCINFO parsing + memory-based building

Switched to parsing srcinfo with channels on all available cpus, speeding
up srcinfo-parsing and queue generation by a lot.

New memory-limit based building will max out the available memory while
not building the same packages at the same time for different marchs,
fixing some long-standing bugs like firefox not building at the same time
because the same ports are used for profile-based optimization. This
also drops the artificial delay on build-start, speeding up things even
more. This also means there is no hard-coded limit on how many packages
can be build at once anymore. As long as there is RAM available, builds will be
started.

ent/ent.go

@@ -11,7 +11,7 @@ import (
 	"entgo.io/ent"
 	"entgo.io/ent/dialect/sql"
 	"entgo.io/ent/dialect/sql/sqlgraph"
-	"git.harting.dev/ALHP/ALHP.GO/ent/dbpackage"
+	"somegit.dev/ALHP/ALHP.GO/ent/dbpackage"
 )
 
 // ent aliases to avoid import conflicts in user's code.
@@ -33,6 +33,32 @@ type (
 	MutateFunc    = ent.MutateFunc
 )
 
+type clientCtxKey struct{}
+
+// FromContext returns a Client stored inside a context, or nil if there isn't one.
+func FromContext(ctx context.Context) *Client {
+	c, _ := ctx.Value(clientCtxKey{}).(*Client)
+	return c
+}
+
+// NewContext returns a new context with the given Client attached.
+func NewContext(parent context.Context, c *Client) context.Context {
+	return context.WithValue(parent, clientCtxKey{}, c)
+}
+
+type txCtxKey struct{}
+
+// TxFromContext returns a Tx stored inside a context, or nil if there isn't one.
+func TxFromContext(ctx context.Context) *Tx {
+	tx, _ := ctx.Value(txCtxKey{}).(*Tx)
+	return tx
+}
+
+// NewTxContext returns a new context with the given Tx attached.
+func NewTxContext(parent context.Context, tx *Tx) context.Context {
+	return context.WithValue(parent, txCtxKey{}, tx)
+}
+
 // OrderFunc applies an ordering on the sql selector.
 type OrderFunc func(*sql.Selector)